‘ 
796 CLASS XIII. 
Sp. Calyptrea equestris Lam., Patella equestris L., Rumpy. Amb. Rariteith. 
Tab. 40, figs. P, @; D’ARGENV. Pl. 2, fig. K, Buatnv. Malacol. Pl. 49 bis, 
fig. 2; habitat Indian Ocean. Comp. on this genus DrEsHayEs Mémoire 
sur la Calyptrée, Ann. des Sc. nat. 11. 1824, pp. 335—344; BropErip 
Descriptions of some new spec. of Calyptreidea, Transact. of the Zool. Soc. i. 
3, 1835, pp- 195—206, Pl. 27—29; OWEN On the Anatomy of Calyptreide, 
ibid. pp. 207—212, Pl. 30. 
Sub-genera: Calypeopsis Luss., Zool., Cog. p. 399, Illustr. de Zool. Pl. 2; 
Lithedaphus OWEN (with calcareous lamina, affixed by its base).—Comp. 
REEVE Conch. syst. 1. pp. 31, 32. 
Crepidula Lam. Shell ovate or oblong, with apex incurved, in- 
clined towards margin. Aperture partly closed by a horizontal 
lamina. 
Comp. Cuvier Mollusg., Mém. 18, pp. 20, 21, Pl. 111. figs. 3—7. 
Sp. Crepidula porcellana Lam., Patella porcellana L., Rumen. Amb, Rari- 
teith. Tab. 40, fig. 0; Buatnv. Malacol. Pl. 49 bis, fig. 3, &c. 
Sub-genus Crepipatella Less., Zool., Cog., Ill. de Zool. Pl. 42. 
Capulus Monrrort, Pileopsis LAM. Shell obliquely conical, 
with apex incurved backwards. Animal with long proboscis, 
deeply chanelled above. Eyes set on tubercles or petioles at the 
outside of tentacles. Neck furnished beneath with a folded velum. 
Branchial series single, composed of narrow lamine. 
Comp. Cuvier l. 1. pp. 19, 20, Pl. 111. figs. 1, 2. 
Sp. Capulus hungaricus, Patella ungarica L., D’ARGENV. Pl. 2, fig. 3, Cuv. 
R. Ani., éd. ill., Moll. Pl. 47, fig. 7, &e. 
Hipponyx DEF. With lamina basal, calcareous. 
Sp. Capulus cornucopie, Pileopsis cornu copie LAM., BuAInv. Malac. Pl. 50, 
fig. 1, Bronn Leth. geogn. Tab. 40, fig. 12; fossil in the calcaire grossier. 
This sub-genus is related to Capulus as Lithedaphus is to Calyptrea. Some 
species still living are known, and some others fossil, all from the tertiary 
formations. 
Phalanx II. Trochoidea. Shell spiral, with aperture entire, 
not canaliferous ; animal mostly furnished with an operculum. 
Pileolus CooKSoN, SOWERBY. 
Comp. DEsHAYES Encycl. méth., Vers. 11. p. 764. Fossil genus. 
Navieella LaM., Septaria Feruss. Shell elliptical, or oblong, 
convex above, concave below, with apex subspiral inflected as far as 
the margin. Labium flattened, narrow, transverse. Operculum 
concealed, flat, irregular, at the upper part of foot. Animal with 
