153 3L^XUAL OF THE MOLLrSCA. 



Animal with a broad muzzle ; tentacles rather short ; lanceolate ; eyes on 

 bulgiugs at the outer bases of the tentacles ; mantle-margin simple, sides 

 plain. Found under stones, between tide-marks, and in shallow water 

 (Cuming). 



Bistr., 50 sp. W. Indies, Honduras, Brit., Medit., Africa, India, Philip- 

 pines, China, Japan, New Zealand, Gallapagos, Chili, 



Fossil, 30 sp. Carb ? chalk—. Brit., France, &c. 



Siih-genera. Criicibulum, Schum. (Dispoteea, Say., Calypeopsis, Less.) 

 Ex. C. rudis, PI. XL, fig. 12. Shell spiuulosc ; internal cup entire ; attached 

 by one of its sides. Distr., W. America, Japan, W. Indies. Found on shells, 

 with its base worn, or smoothed by a shelly deposit (Gray). Between this 

 section and the next there are several intermediate forms. 



Trochita, Schum. (Infundibiilum, J. Sby., Galerus, Humph. Trocha- 

 tella and Sipliopatella, Lesson.) T. radians, PL XL, figs. 13, 14. (=PateUa 

 trochoides, DiUw.) T. sinensis, PI. XL, fig. 15. Shell circular, more or less 

 distinctly spiral ; apex central ; interior \vith a more or less complete sub- 

 spiral partition. Distr., chiefly tropical, but ranges from Britain to New 

 Zealand. T. prisca (McCoy) is found in the carb. limestone in Ireland ; and 

 several large species occm' in the London clay and Paris basin. The recent 

 C. sinensis — the " China-man's hat" of collectors — is found on the southern 

 shores of England, and in the IMediterranean, in 5 — 10 fms. water (Forbes). 

 Its lingual dentition is given by Loven ; — median teeth broad, hooked, den- 

 ticulated ; uncini 3, the fu'st hooked and serrated, 2, 3 claw-shaped, simple. 

 Ckepidula, Lam. 



Etym., crepidula, a small sandal. 



Type, C. fornicata, PI. XL, fig. 16. St/n., crypta, Humph. 



Shell oval, limpet-like ; ^ith a postei'ior, oblique marginal apex ; interior 

 polished, with a shelly partition covering its posterior half. 



The crepididffi resemble the fresh -water naviceUse in fonn ; but the inter- 

 nal ledge which mimics the columella of the nerite, is here the basis of the 

 adductor muscles. 



They are sedentary on stones and shells, in shallow water, and are some- 

 times fouud adhering to one another in groups of many successive generations. 

 The specimens or species which live inside empty spu-al shells are very thin, 

 nearly flat, and colomiess. 



Distr., 40 sp. W. Indies, Honduras, Medit., W. Africa, Cape, India, 

 Australia, W. America. 



Fossil, 14 sp. Eocene — . France, N. America, Patagonia. 

 PiLEOPSis, Lam. Bonnet-limpet. 



Etym., pileos, a cap, and opsis, like. 



Syn., capulus, ]Montf. Brocchia, Bronn. 



Type, P. hungaricus, PI. XL, fig. 1?. P. militaris, PI. XL, fig. 18. 



