p"-'- 



/" 



}^' 232 



marked black elongate streak, margined with a scarcely 

 perceptible yellow border extending over five of the upper 

 rays of caudal fin, which latter is somewhat rounded 

 terminally. 



Total length 4| inches 



Length of body ... 



„ „ head ... 



„ „ snout... 

 Dia, of eye 



Greatest depth of body 

 Least 



6 mil. 

 l\ inches 



4 » 



DESCRIPTION OF A NEW FOSSIL SHELL FEOM 

 THE EOCENE BEDS, TABLE CAPE. 

 By Eobt. M. Johnston, F.L.S., Etc. 

 [_Bead July 7, 1884.] 

 Genus Ckepidula (Lam.) 

 Shell oval, limpet-like, with a posterior oblique, marginal 

 apex ; interior polished, with a shelly partition covering its 

 posterior half. They are sedentary on stones and shells, in 

 shallow water, and are sometimes found adhering to one 

 another in groups of many successive generations. The 

 specimens which live inside empty spiral shells are very thin, 

 nearly flat, and colourless. Distribution. — West Indies, 

 Honduras, Mediterranean, West Africa, Cape, India, Aus- 

 tralia, West America. Fossil. — Eocene. France, North 

 America, and Patagonia. (Woodward's Manual of Mol- 

 lusca, p. 277.) 



Crepidula umbilicata {Nov. sp.). 



Shell somewhat roundly ovate, convex above, with 

 nucleus submarginal and exserted. Whorls, three, rapidly 

 increasing. Upper surface somewhat rugose, with three or 

 four fine spiral ridges, which are here and there interrupted, 

 the whole crossed with fine lines of growth. The internal 

 ledge, occupying nearly the posterior half of shell, is concave 

 with a somewhat wide and profound umbilicus; aperture 

 deltoid ; labrum thin, and obtusely angled anteriorly. 



Length, 8 lines ; breadth, 7 lines ; depth, 3| lines. 



Only one example from the eocene beds, Table Cape, 

 associated with one or two species of the same genus not yet 

 described. 



