Part 5

I regret not having Dr. Horsfield's work to refer to; but I believe I am perfectly safe in stating from memory that these seven he considered typed in the genera, Saturnia, Lasiocampa, Cossus, Cerura, Arctia, Laria, and Limacodes: two of these he manages to unite to other two, in order to reduce the number to five, but I forget which.

As the genera which I must mention ought necessarily to be drawn entirely from one work, in consequence of authors differing as to their contents, I have adopted those in Mr. Curtis's Guide, invariably: below is a list of the genera he has given in this section, with my own idea of their situation attached to each, and the addition of six genera, which Mr. Curtis does not consider as belonging to the sub-class Phalænæ:

789 Trochilium 2 Cossi. 790 Ægeria 2 Cossi. 791 Hepialus 2 Cossi. 792 Cossus 2 Cossi. 793 Zeuzera 2 Cossi. 794 Stauropus 3 Notodontæ. 795 Pygæra 3 Notodontæ. 796 Clostera 3 Notodontæ. 797 Notodonta 3 Notodontæ? 798 Pterostoma 3 Notodontæ. 799 Petasia Sub-class Noctua. 800 Episema Sub-class Noctua. 801 Colocasia 6 Lariæ. 802 Dimorpha 3 Notodontæ? 803 Cerura 3 Notodontæ. 804 Ptilophora 3 Notodontæ? 805 Endromis Order uncertain. 806 Saturnia 7 Phalænæ. 807 Eriogaster 1 Bombyces. 808 Clisiocampa 1 Bombyces. 809 Lasiocampa 1 Bombyces. 810 Odenestis 1 Bombyces. 811 Gastropacha 1 Bombyces. 812 Hypogymna 6 Lariæ. 813 Orgyia 6 Lariæ. 814 Laria 6 Lariæ. 815 Arctia 6 Lariæ. 816 Arcturus 6 Lariæ? 817 Spilosoma 5 Arctiæ. 818 Phragmatobia 5 Arctiæ. 819 Penthophera Order uncertain. 820 Eyprepia 5 Arctiæ. 821 Eulepia 4 Lithosiæ. 822 Hypercampa 4 Lithosiæ. 823 Callimorplia 4 Lithosiæ. 824 Deiopeia 4 Lithosiæ. 825 Lithosia 4 Lithosiæ. 826 Nudaria Sub-cl. Phryganea. 827 Psyche Sub-cl. Phryganea. 828 Heterogena Order uncertain. 829 Limacodes Order uncertain. 854 Acronycta 5 Arctiæ. 942 Platypteryx 3 Notodontæ. 943 Drepana 3 Notodontæ. 944 Cilix 3 Notodontæ.

Natural Order--Bombyces. Has an elongate cylindrical downy larva, which rolls itself into a ring when touched; the pupa changes in a close gummy oval cocoon, remarkably small for the size of the imago. Among the exotic species of Lasciocampa, we find in the males particularly slender bodies, expansive wings, the inferior grooved to receive the abdomen, and diurnal flight, all of them characters so indicative of an approach to Papilio, that we scarcely hesitate a moment in assigning it the approaching station, not but I expect fully that time will eventually furnish us with a connexion on each side yet more conclusive. The second genus of Bombyces is probably Odenestis, and the third Gastropacha, whose prominent and elongated palpi appear to point out an approach toward a tribe of insects with the same peculiarity, of which there are several to be found in the following order:

See a Papilio with the antennæ of a Lasciocampa. Drury, Vol. III. pl. v.

Natural Order--Cossi. The larva is depressed; naked, except a very few scattered hairs; has sixteen feet; lives through one or more winters; never rolls itself in a ring when touched; feeds on the solid interior woody parts of vegetables. The pupa generally changes in a tough oval cocoon, interwoven with particles of its food. It has a double ring of raised denticulations of each segment of the abdomen, by means of which it is endowed with a considerable power of locomotion. The genus Zeuzera is very near the point of contact with the Bombyces. In Zeuzera there is much resemblance to the antennæ of Gastropacha. One genus, or group of genera, I expect will prove to be Stygia, a native of New-Holland. A second, at the point of contact with Sesia in Sphinx, must be Ægeria; thus retaining its place among British insects, immediately between Sesia and Cossus. This is the first of a series of the most beautiful instances of approach, or rather, of what ought to be termed relations of analogy, that any system has ever previously disclosed. As a few words will again be necessary on this subject, I refrain from any further observation here, than merely requesting the reader to examine how minutely the Sphinx characters are appropriated by a true lignivorous Phalæna, which cannot be said, in any of its prior and principal states, to have the most distant approach to Sphinx. A third genus is, probably, the strange and paradoxical exotic Oiketicos, which has been minutely described in the Linnæan Transactions; and a fourth is Hepialus. This genus has some slight points in which it differs from the others of the order already known, the larva being radicivorous only, seldom or never ascending internally the stems of plants: it changes in the earth.

It is a most singular chance that these genera should have been placed so naturally, as the cause of this proximity has never before been even hinted at.

Another type of Hepialus is figured in Drury, Vol. II. pl. xiii. 2.

Natural Order--Notodontæ. The larva is naked, has sixteen feet, and is, in different genera, furnished with excrescences, and apparent distortions in various parts of the body. The eighth or last pair of feet, and three last segments of the abdomen, are elevated; when the insect is at rest, the head and first segment are raised in a similar manner. In one genus (containing Camelina) the head and extremity of the abdomen nearly meet over the back, when raised in this singular manner. The posterior feet are frequently useless in walking; in some genera, entirely obsolete. The pupa is smooth, in a cocoon, mostly among dead leaves on the surface of the ground: sometimes it is glutinous, and interspersed with fragments of wood, like the last. I confess I am exceedingly puzzled both with the contents and extent of this order; but this arises from my having seen so few of the species in the larva state. Ptilophora plumigera, figured by Mr. Curtis, I had always considered a Notodonta; but the larva evidently excludes it from the order, and, I should imagine, places it among the Noctuæ; where among them I know not, for I have not the slightest idea of any congeners, either of the larva or imago. The larva from which a collector of Lepidoptera could expect to obtain such an imago would be unicolourous, stouter in the middle, elevated in the penultimate segment, and more attenuated towards the head. Pygæra appears doubtful at first, but when observed quite at rest, and in a perfectly natural position, elevates the head and tail, though in a much less degree than the typical genus. Mr. Curtis's genus Notodonta contains several good species, which may be considered as typing the order, as Ziczac, Tremula, and Dictæoides. The first species, Trepida (the Peridea serrata of Mr. Stephens,) seems more nearly related to Endromis. Both these may, however, probably belong to the order Notodontæ, and be situate near the approach to the central order Phalænæ. Petasia cassinea and Episema cærleocephala appear to be genuine Noctuæ, and very near Chareas graminis, and Rusina ferruginea, as far as my very imperfect knowledge of these four species will allow me to judge. Clostera is another departure from the type; but this may be accounted for, in some degree, by its close proximity to Hepialus, from which genus it borrows its remarkably short antennæ, and other peculiarities. It seems a strange perversion of judgment to place Platypteryx at the end of or among the Geometræ; but Linnæus did so, and that is enough. Hubner, Haworth, and a few others, positively ventured, in this glaring instance, to refer this genus to the Bombyces; but their ideas were thought to be wrong, and their judgment was, nem. con. reversed. I have elsewhere expressed a wish that my readers should convince themselves, and the frequent occurrence of the larvæ of Platypteryx and Cerura would afford any naturalist abundant opportunity of ascertaining, that they can be referred to but one order. The approach of Platypteryx and Cilix to the Pyralides, in assuming so much of their characters, is very interesting, and is a most striking departure from the typical form. These genera also approach the Lithosiæ, but not so nearly as some exotics.

British Entomology, pl. 328.

As the larva so decidedly forbids the introduction of this insect among the Notodontæ, and places it among the Noctuæ, it probably in some degree approaches Geometra pennaria in the adjoining sub-class.

Natural Order--Lithosiæ. The difference between Lithosiæ and Arctiæ is rather difficult to point out; yet a difference exists, which it is perfectly impossible not to detect. The larva of Lithosiæ has sixteen feet, is very active, is moderately hairy, does not readily roll itself in ring, but occasionally assumes that attitude. The pupa is smooth, changes in a slight web, in which the hairs are intermixed. The approach of Lithosia to the genus Yponomeuta, in Tinea, scarcely need be pointed out. It will be observed, that Mr. Samouelle was aware of this approach, and placed the genera Lithosia and Yponomeuta following each other. The splendid Callimorpha dominula, although, to all appearance, a real Arctia, must be included in this order, and placed in contact with the following one.

See note for the genera of Lithosia.

Ent. Useful Com. p. 249.

Natural Order--Arctiæ. Larva, with sixteen feet, generally very hairy, bear-like; rolls itself in a ring when touched; pupa smooth, in a slight web. Whether the whole of Mr. Curtis's genus Acronycta must be included in this order, I am not able positively to say: the genus Apatela of Mr. Stephens certainly must, and until I have obtained sufficient information to decide on Acronycta, we must bring Mr. Stephens's genus only into the order, leaving the remainder of the species undisposed of. The development of the antlia in Acronycta discovers as near an approach to Noctua, as Lithosia does to Tinea; but the bear-like, cocoon-spinning larva place these insects in close alliance with the true Arctiæ.

Natural Order--Lariæ. Larva, with sixteen feet, and furnished with various brushes, or fascicles of hair, on different parts of the body, but mostly on the anterior dorsal segments; it rolls itself in a ring when touched. The genus Porthesia of Mr. Stephens may be considered a near approach to Eriogaster, in the following order, Bombyces, in many of its peculiarities, as the abdominal hair with which it covers its eggs, in its antennæ, &c. Orgyia antiqua, on the other hand, is in habit, expansion of wing, slender body, and apterous female, a close approach to the Geometræ, near the genera Hybernia and Nyssia; in fact, were it not for the larva, that is, were the larva unknown, we should have no hesitation about placing this insect with the Geometræ.

Natural Order--Phalænæ. Larva, with sixteen feet; it has a circle of wart-like protuberances on each segment, from each of which spring a few strong bristles; pupa, smooth, with a few bristles at the tail; changes in a cocoon, which is singularly left partly open at one end. We have but one species of this order in Britain, Saturnia carpini; but among exotics there is a great variety, some remarkable for the immense expanse of their wings. Probably Phalæna Atlas of Linnæus is the centre of the group, and, if so, the centre and type of the class Lepidoptera.

Saturnia carpini is the Pavonia minor of Linnæus, who, apparently, considered it a variety of a completely different species: the retention of a name thus originating in error is not justifiable.

Drury has some fine figures of this order, particularly Vol. I. pl. xviii. 2; Vol. II. pl. v. 1, pl. vi. 2, pl. xi. 1, 2, pl. xiii. 2; Vol. III. pl. xix. pl. xxiv. pl. xxv. pl. xxxiv.

I have previously given, in a note, a list of the genera which are usually considered as Bombyces, and ought, therefore, if properly placed, to be included in the sub-class Phalæna; five of those genera yet remain, and at present must be excluded from the sub-class: Penthophera, Heterogena, and Limacodes, because I know nothing of their history; Nudaria and Psyche, because, in the larva, pupa, and imago states, they have the habit and appearance of another class (Neuroptera). The time of their dwelling with Lepidoptera is over and gone; they have already occupied too long a position to which they were not entitled. The difficulty of assigning a situation to Limacodes I hope to see removed, as the larva is occasionally to be met with. I must also remark, that although I have proposed a situation for Endromis, I feel very doubtful as to its being the correct one. These doubts and difficulties will probably gain me much censure; but I must endeavour to shelter myself in some degree, by observing, that I am the first who has ever deviated from the original Linnæan arrangement of Lepidoptera, the first who has ever thought of appealing to nature in support of theory, or rather has waited for nature to supply him with theory; and surely some allowance is to be made for a first attempt of any kind. I would also plead the poverty of our British Fauna in the sub-class, and my almost entire ignorance of exotic Phalænæ. Even supposing myself acquainted with all our indigenous species, they will barely furnish a systematist with a clew to the truth: you may pick up a single link of a chain, yet fail to discover the length of that chain, or the situation in that chain which the link originally possessed.

Having, then, pointed out, as clearly as my limited knowledge of the subject will permit, not only the principal contents of the class Lepidoptera, but endeavoured to establish them in appointed and fixed stations, and to show their mutual approaches, at least those of the most striking kind and essential to my purpose, I must now proceed to make a few remarks on the nature of these approaches. It will be observed, that they are, almost without an exception, what Mr. MacLeay considers relations of affinity, that is, the relation is between species which, in their imago state, have a real and positive similarity to each other; so much so, that entomologists, unacquainted with the prior states, and frequently even in direct defiance of their own knowledge of those states, place them in orders, and even sub-classes to which they do not belong; to which fact all our systems and catalogues bear most ample testimony. This similarity is by no means confined to a cursory glance at the insects, but bears the test of a minute anatomical investigation, the antlia, palpi and antennæ demonstrating the approach quite as forcibly as the form and appearance of the whole insect. Where a tribe has short biarticulate palpi, a genus departing from the type will assume elongated and triarticulate palpi, should another tribe with those characters approach it: again, should a tribe with long antlia approach a tribe whose character it is to have none, we shall be sure to find a genus without antlia at the point of approach. On the other hand, the very egg, the larva, the pupa, the mode of feeding and description of food, the mode of metamorphosis, and, in fact, every prior quality, or state, from which distinctions could be obtained, differ so decidedly, that the characters of these often bear as near an approach to those of Hymenoptera, Neuroptera, and even Coleoptera, as to those of their own kindred, into immediate contact with which these approaches will be found inevitably to bring them. What term can then be applied to designate the real value of this species of approach? Supposing the terms analogy and affinity to have had good, sound, and distinct meanings, as originally employed and explained by great naturalists, they have now been so confused, confounded, and utterly misunderstood by ignorant persons, that either of these terms is entirely out of the question: in fact, a suitable term by which to designate this peculiar species of relation or approach, I neither know where to find, or how to invent; and, therefore, I shall purpose simply to call it relation of larva, relation of pupa, or relation of imago, as the case may be.

No individual need say with more heartfelt sincerity--"Preserve me from my friends," than Mr. MacLeay; let the naturalist read the Horæ Entomologicæ, and he will pause in admiration at the vigorous, manly display of intellect, which, frankly and eagerly seeking truth, throws a golden lustre over every page; and, I confess, my eyes were opened to the suspicion that all was not pure gold, by the awkward and abortive attempts of commentators to prove it so. Puerile schemes of applying the quinary system in detail, and sundry vapourings about affinity and analogy, have so mystified these subjects, that they already totter to their very foundations, and must speedily fall; while the existence of circles must stand for ever as a discovery of which Britain is proud.

In one instance, the relation of imago is, from several combining causes, which it will be unavailing to recapitulate, uncertain enough--that of Barbicornis and Lasiocampa; but I would ask the impartial reader, is it half so far-fetched and untenable as those in common use? Can human sagacity, in sheer wantonness, invent combinations more unnatural than ----, twenty or thirty of which we could all point to in our own cabinets? For the value of the other relations (eleven others) I appeal to the judgment of the assiduous collector, the experienced observer, the real nature-loving naturalist,--to him who has spent days in the woods, and not only captured but observed these delightful beings,--to him who never invented or supported a theory,--to him who is pledged to no system, to no party,--I ask him, nothing doubting of his concurrence, whether these relations do not too plainly bear the impression of nature's seal, to allow him to doubt one instant of their reality.

In the next place a question occurs, how is the relative position of the sub-classes proved to be correct, seeing it is so totally at variance with what we have from our childhood been perfectly satisfied with? It is proved correct, simply and solely by the harmony with which each flows into each,--with which neighbour meets neighbour,--comparable somewhat to that exquisite feeling which induces a man to bend to the peculiarities, and perhaps even little failings of a friend, until he makes them almost his own. It can hardly be supposed that the sub-classes naturally fell into the positions which I have assigned to them, without some little endeavour, on my part, to produce this harmony. This was far from the case. The discovery, if it be one, was the result of serious and deliberate study. Even after arriving at their present state, I have twice endeavoured to alter these positions, once in hopes of making some of the Tortrices meet the Papilionidæ, as I had an idea that that very assiduous and ingenious naturalist, Dr. Horsfield, had mentioned the discovery of such an approach. In vain, however, did I strive to discover such an approach, in either larva, pupa, or imago, while these points of resemblance were most abundant between the Geometræ and Papiliones; the pupa, as though in sport, being now suspended by the tail, now girted round the waist, now enveloped in a silken web; sometimes round-headed, sometimes pointed, sometimes eared; now smooth, anon angulated, black, brown, yellow, pure green, clouded, or spotted: of these, and a thousand other peculiarities, which tended to corroborate my ideas of arrangement, I refused invariably to avail myself, trusting to one guide only, which seems as steadfast as a rock: that relation of imago constitutes approach of divisions; relation of larva is the tie which holds divisions together. The second alteration I endeavoured to make, was to place the Papiliones in the centre, a situation to which their splendour and magnitude would really appear to give them a title. This idea seems every way so plausible, and so likely to be proposed by entomologists, should any such see merit enough in this system to give their attention to its minutiæ, that I am compelled to consider it more at large.

This question has occurred.

It is so long since I have seen Dr. Horsfield's beautiful work, that I will not pledge myself to the doctor's making this assertion.

To a sub-class selected for a centre, two qualities are indispensably requisite. They have been previously given from Mr. MacLeay, who, it will be remembered, discovered that one of each of his five groups contained types of the other four, besides a type peculiar to itself. This quality must hold good in any group thus selected for a centre; it must contain types of the six surrounding groups in the first place. Now, is this applicable to Papilio? Have we not already experienced the greatest difficulty in finding three good approaches, the smallest number which a sub-class can possess? How then can we hope, by any good fortune in discovery, to make ourselves masters of three other entirely new ones, and these to sub-classes to which it is confessedly the most unlike? Phalæna, on the contrary, presents us with Lasiocampa, Ægeria, Cilix, Lithosia, Apatela and Orgyia, five of which genera beautifully typify the approximating sub-classes. The preference on this score then is decidedly with Phalæna.

The second position, that it should contain a type peculiar to itself, is almost a matter of course; but my own idea is, that the very centre should not only be a type of the genus, or order, or sub-class, but of the class itself of which it is the centre. From this position, then, a further and still more important question arises,--What is the type of Lepidoptera? The parts which afford the generic characters of Lepidoptera, and, I believe, generic characters in the perfect state are the only ones of any value, are these--the mouth, palpi, antennæ and wings; and, as no medium can constitute a type, the excess of these characters, whether superlatively or diminutively considered, must be resorted to as the most probable means we possess of discovering what this type may really be. First, then, the mouth. In Lepidoptera, we find two distinct characters in this;--first, its entire absence; secondly, its being furnished with prodigiously long antlia. The first character is that of Phalæna, the second that of Sphinx. Next, the palpi are either entirely obsolete or exceedingly prominent, the first in Phalæna, the second in Pyralis. Thirdly, the antennæ are remarkably pectinated, or clavated, or setaceous: the first character is that of Phalæna, the second that of Papilio, the third that of Noctua. Fourthly, the wings are enormously expansive in proportion to the body, or remarkably small,--the first is the character of Phalæna, the second that of Sphinx. It need scarcely be added, that all these characters are to be met with in every intermediate degree of intensity. Now, it appears, that Phalæna possesses an extreme of each of the four principal characters, Sphinx of two, Noctua of one, and Papilio of one; therefore Phalæna is the typical genus, Phalænæ the typical order, and Phalæna the typical sub-class of Lepidoptera: and a necessary conclusion from this fact is, the type of Lepidoptera is an insect without antlia or palpi, with very pectinated antennæ and enormously expansive wings, and we may add nocturnal flight: so that such peculiar characters as the thick full body and prodigiously long antlia of Sphinx, the clavate antennæ, erect wings, and diurnal flight of Papilio, argue a departure from, and not an approach to, the type.