796 CLASS xni. 



Sp. Calyptrcea equestris LAM., Patella equestris L., RUMPH. Ami. Raritcitk. 

 Tab. 40, figs. P, Q; D'ARGENV. PI. 2, fig. K, BLAINV. Malacol. PI. 49 bis, 

 fig. 2 ; habitat Indian Ocean. Comp. on this genus DESHAYES Memoire 

 sur la Calyptree, Ann. des Sc. nat. m. 1824, pp. 335 344; BRODERIP 

 Descriptions of some new spec, of Calyptrceidea, Transact, of the Zool. Soc. I. 

 3, 1835, pp. 195 206, PI. 27 29; OWEN On the Anatomy of Calyptree idea, 

 ibid. pp. 207 212, PI. 30. 



Sub-genera: Calypeopsis LESS., Zool., Coq. p. 399, Illustr. dcZool. PI. 2 ; 

 Lithedaphus OWEN (with calcareous lamina, affixed by its base). Comp. 

 REEVE Condi, syst. n. 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 Mollusq., Mem. 18, pp. 20, 21, PI. m. figs. 3 7. 



Sp. Crepidula porcellana LAM., Patella porcellana L., RUMPH. Artib. Rari- 

 teitk. Tab. 40, fig. o ; BLAINV. Malacol. PI. 49 bis, fig. 3, &c. 



Sub-genus Crepipatella LESS., Zool., Coq., III. de Zool. PI. 42, 



Capulus MONTFORT, 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 laminae. 

 Comp. CUVIER 1. 1. pp. 19, 20, PI. in. figs, i, 2. 



Sp. Capulus hungaricus, Patella ungarica L., D'ARGENV. PI. 2, fig. 3, Cuv. 

 R. Ani., ed. ill., Moll. PI. 47, fig. 7, &c. 



Hipponyx DEFR. With lamina basal, calcareous. 



Sp. Capulus cornucopice, Pileopsis cornu copice LAM., BLAINV. Malac. PI. 50, 

 fig. i, BRONN Leth. geogn. Tab. 40, fig. 1 2 ; fossil in the calcaire grossier. 

 This sub-genus is related to Capulus as Lithedaphus is to Calyptrcea. 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. meth., Vers. in. p. 764. Fossil genus. 



Navicella 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 



