Part 46

MALACOZOA. Bl. ([Greek: Malakos], malacos, soft; [Greek: Zôon], zoon, animal.) The type or general appellative in De Blainville's system, including all molluscous animals, excepting those with multivalve shells.

MALDANIA. Lam. The second family of the order Annelides Sedentaria. The only genus of shells described in this family is Dentalium, fig. 2, to which may be added Pharetrium, König. fig. 3. It is doubtful however whether the latter do not belong to an unknown genus of Pteropodous Mollusca.

MALEA. Valenciennes. A genus composed of DOLIUM latilabrum, Kiener, and other similar species.

MALENTOZOA. Bl. ([Greek: Malakos], malacos, soft; [Greek: en], in, [Greek: temnô], temno, cut; [Greek: Zôon], zoon, animal.) Or articulated mollusca. The sub-type in De Blainville's system, comprehending those with multivalve shells.

MALLEACEA. Lam. A family belonging to the order of Conchifera Monomyaria. Containing the following genera of irregular pearly bivalves.

1. AVICULA. Hinge linear, simple, including Meleagrina. Fig. 163, 164.

2. PERNA. Hinge with linear grooves, including Pulvinites. Fig. 166, 170.

3. GERVILLIA. Shaped like Modiola, with irregular grooves. Fig. 162.

4. CRENATULA. Hinge with a series of pits. Fig. 168.

5. CATILLUS. Like Perna, but more regular and convex. Fig. 167.

6. MALLEUS. A triangular disc on the hinge, and two auricles. Fig. 165.

MALLEUS. Auct. (Malleus, a hammer.) Fam. Malleacea, Lam. Margaritacea, Bl.--Descr. Equivalve, inequilateral, foliaceous, trilobate, undulated, irregular, attached by a byssus passing through a sinus in one valve; hinge rectilinear, lengthened by two auricles; with a small disc under the umbones, containing the ligament, and a groove containing the cartilage; muscular impressions one in each valve, large, uniform, and one or two others extremely minute.--Obs. Malleus Vulgaris, the type of this genus, is a most singular shell, commonly called the "Hammer Oyster," from the peculiarity of its shape. It belongs to the Linnæan genus Ostrea, from which it differs in being attached by a byssus. Fig. 165, M. Vulgaris. Tropical.

MAMILLARIA. Sw. A sub-genus of NATICA, corresponding with Polinices of Montfort, having the spire small and the umbilicus filled. Ex. Natica Mamilla, Auct. fig. 327.

MAMMILLATED. (Mammula, a little teat.) A term applied to the apex of a shell when it is rounded like a teat. Ex. Voluta Vespertilio, fig. 433.

MARGARITA. Leach. (Margarita, a pearl.) A genus of small shells resembling the genus Trochus, from which it differs in having an operculum consisting of few whorls. M. tæniata, fig. 362. Mr. G. B. Sowerby, sen. has enumerated 15 species in a list accompanying the figures published by the author of this manual in Nos. 132 to 134 of his Conchological Illustrations.

MARGARITACEA. Bl. The third family of Lamellibranchiata, Bl. The shells belonging to it are described as irregular, inequivalve, inequilateral, black or horny without, pearly within; hinge auriculated, scarcely developed, and without teeth. The ligament is variable and there is a large sub-central muscular impression. This family contains the genera Vulsella, Malleus, Pinna, Crenatula, Inoceramus, Catillus, Pulvinites, Gervillia and Avicula.

MARGARITACEOUS. (Margarita, a pearl.) Pearly.

MARGARITANA. Schum. A sub-genus of Uniones, composed of species having "one cardinal tooth." ALASMODON, Say. MYA Margaritifera, Linn.

MARGARITIFEROUS. (Margarita, pearl; fero, to bear.) Pearl-bearing. Applied to shells which form pearls; as Meleagrina Margaritifera, or Pearl-bearing Oyster.

MARGINAL. Near the margin or edge.

MARGINATED. (Margo, edge.) Having an edge or border thicker than the rest of the shell, from which circumstance the little genus Marginella derives its name.

MARGINELLA. (A little rim or border.) Fam. Columellaria, Lam. Angyostomata, Bl.--Descr. Ovate, smooth, shining, with a short, sometimes hidden spire; aperture narrow, emarginated; columella with several oblique folds; outer lip neatly reflected.--Obs. This genus of pretty little shells differs from Voluta, in the reflection of the outer lip. The animal covers the greater part of the shell with the mantle, and by continually depositing vitreous matter gives it a bright polish, which, together with the delicately neat arrangement of colours in most species, renders them exceedingly beautiful. The Marginellæ are marine and tropical. A few fossil species are found in the Calc-grossier. Fig. 437. M. Glabella. GLABELLA, Sw.

MARGINULINA. D'Orb. A genus of microscopic Foraminifera.

MARINE CONCHACEA. See CONCHACEA.

MARINE TESTACEA. Those shell-fish which inhabit seas, lakes, &c. of salt water, in distinction from the Aquatic Testacea, or those which are found in rivers, ponds or stagnant pools of fresh water: and also from the Land Testacea, which live on land and breathe air. The great proportion of shells belong to the former class, those of the latter two classes being limited in their number, and in the genera to which they belong.

MARINULA. King. A genus of small shells resembling Auricula and Pedipes, described as "Ovate, sub-solid, with aperture ovate entire; columella bidentate, uniplicated towards the base, with large sub-remote teeth; the largest uppermost; no operculum."

MARMAROSTOMA. Sw. A genus of "Trochidæ," Sw. thus described: "Umbilicus deep; spire of few whorls, much depressed, and obtuse; inner lip obsolete; base even more produced than in Senectus, but never distinctly channeled. M. versicolor. Mont. 176. f. 1740, 1741, undulata. Chem. 169. f. 1640, 1641," Sw. p. 348.

MARPESSA. Gray. A sub-genus of Clausilia, C. bidens, &c. Auct. Gray's Turton, p. 212.