Part 62

PTEROPODA. Bl. The second family of Nucleobranchiata, Bl. the shells of which are described as symmetrical, extremely thin, transparent, longitudinally enrolled, either forwards or backwards. The animals are remarkable for a pair of broad, flat, natatory organs or membranaceous fins, from which the family derives its name. It contains, in the system of De Blainville, the genera Atlanta, Spiratella, and Argonauta, to which may probably be added PHARETRIUM, König; ENTALIS, Defrance.

PULLASTRA. Sow. Fam. Conques Marines, Lam.--Descr. Equivalve, ovate or oblong, transverse, inequilateral; hinge with three diverging cardinal teeth in each valve, notched at the terminations; muscular impressions two in each valve; palleal impression having a large sinus; ligament external, partly hidden by the dorsal margin.--Obs. This genus includes the Venerirupes of Lamarck, and several species of his Veneres, they are found in the sand on the shores of temperate and tropical climates. Fig. 120, P. textile.

PULMONOBRANCHIATA. Bl. The first order of the first section of Paracephalophora monoica, containing the families Limnacea, Auriculacea, and Limacinea.

PULVINITES. Defr. (Pulvinus, a cushion.) Fam. Malleacea, Lam.--Descr. Sub-equivalve, inequilateral, compressed, thin, slightly gaping posteriorly; one valve flat, the other rather concave; hinge linear, short, divided into perpendicular grooves; muscular impressions two, one sub-central, the other above it, nearer the hinge.--Obs. This fossil shell is imperfectly known, and it is difficult to give a sufficient reason for separating it from Perna. It comes from the Baculite limestone of Normandy. Fig. 170, P. Adansonii.

PUNCTATED. (Punctatus, spotted or dotted.) For example, see Conus Nussatella. Fig. 460.

PUNCTICULIS. Sw. A sub-genus of "Coronaxis," Sw. (Conus) described in Swainson's Malacology, page 311.

PUNCTURELLA. Lowe. CEMORIA, Leach.

PUPA. Auct. Fam. Colimacea, Lam.; Limacinea, Bl.--Descr. Cylindrical, generally ribbed; spire long, obtuse, composed of numerous slowly increasing whorls; aperture sub-quadrate, rounded anteriorly, entire; outer lip thickened; columella plaited.--Obs. This genus is composed of land shells very variable in form, differing from Bulinus in the numerous slowly increasing whorls of the spire, and in the plicæ on the columella, and from Clausilia in the want of a clausium. Britain, Southern Europe, East and West Indies, Mexico, &c. P. Uva. Fig. 291.

PUPELLA. Sw. A sub-genus of Clausilia. Lardn. Cyclop. Malac. p. 334.

PUPILLA. Leach. A sub-genus of Pupa, P. marginata, Auct. (Gray's Turton, p. 196.)

PUPINA. Vignard. MOULINSIA, Grateloup. Fam. Colimacea, Lam.--Descr. Pupiform, sub-cylindrical; last whorl less than the preceding; surface brilliantly polished; suture of the spire enamelled; aperture circular; peritreme thickened; a notch at the base of the inner lip; operculum horny, spiral.--Obs. The species upon which this genus was originally founded, and described in the "Annal des Sciences Naturelles," tome 18, p. 439, (December 1829,) is a small pupiform shell, having nothing to distinguish it but the enamelled suture and the notch in the aperture; characters quite insufficient in themselves for the purpose of generic distinction; at the same time sufficient to lead M. De Ferussac to the suspicion of its having an operculum. The next species, described by Grateloup under the name of Moulinsia Nunezii, (Ann. Soc. Linn. Burd, Nov. 1840), presents more remarkable characters, having the spire turned backwards and the penultimate whorl disproportionately large. Seven additional species have been lately brought to this country from the Philippine Islands by Mr. Cuming. They will be described by the author in the Zoological Proceedings for 1841, and an illustrated monograph of the whole genus is published in the Thesaurus Conchyliorum, Part I, by the Author. It may be observed that in one of the new species, the notch in the peritreme almost disappears, leaving a very slight sinus. Fig. 524, 526, 527, 528.

PURPURA. Auct. ("The shell-fish from which purple is taken," Plin.) Fam. Purpurifera, Lam. Entomostomata, Bl.--Descr. Oval or oblong, thick; spire for the most part short, sometimes rather longer; external surface generally sulcated, granulated, tuberculated or muricated; aperture long, oval, somewhat dilated, emarginated anteriorly; outer lip crenated, acute; columella flattened; operculum horny, with the nucleus lateral, thin towards the columella.--Obs. True Purpuræ to be found in the Lamarckian genera Buccinum, Ricinula, and others. They may be generally distinguished by the flatness of the columellar lip, and by the short canal or emargination, which is not reflected or raised, as in Buccinum. The species are very numerous and very variable in form, inhabiting the seas of temperate and tropical climates. The animals secrete a purple liquor, which has been used advantageously for dyeing; the origin of the famous Tyrian dye. Fig. 414, P. persica.

PURPURIFERA. Lam. (Purpura, purple; fero, to carry.) A family belonging to the second section of Lamarck's order Trachelipoda, the shells of which are described as having a very short recurved, or ascending canal, or else only a notch between the inner and outer lips. The name Purpurifera has been given to the family because the animals which it includes, and particularly the genus Purpura, contain the colouring matter from which the ancients obtained the well known splendid purple. This family contains the following genera.

1. CASSIS. Outer lip thick, reflected, denticulated, canal turned suddenly over the back; spire short; including Cassidea and Cypræcassis. Fig. 410 to 412.

2. CASSIDARIA. Canal turned gently upwards. Fig. 407, 408.

3. ONISCIA. Inner lip granulated; canal short. Fig. 409.

4. BUCCINUM. Outer lip thickened not reflected; canal short; including Cyllene and Phos. Fig. 416, 421, 422, 425.

5. NASSA. The same, with a notch or tooth at the extremity of the columella; including Cyclops. Fig. 423, 424.

6. DOLIUM. Swelled, grooved spirally; outer lip not reflected. Fig. 420.

7. PURPURA. Aperture large; columellar lip flat; including Tritonidea. Fig. 414, 415.

8. MONOCEROS. The same, with a tooth on the outer lip. Fig. 417.

9. CONCHOLEPAS. Patelliform; aperture as large as the shell. Fig. 417.

10. RICINULA. Columellar and outer lips granulated, denticulated, outer lip digitated; including Tribulus. Fig. 413.

11. TRICHOTROPIS. Hairs on the epidermis, along the keels. Fig. 429.

12. TEREBRA. Elongated, with a spiral groove near the suture of the whorls. Fig. 428.

13. BULLIA. Short; aperture wide; outer lip marginated. Fig. 427.

14. EBURNA. Like Buccinum, but the outer lip not thickened. Fig. 426.

15. HARPA. With varices at regular intervals. Fig. 419.