NUCULID.E. 53 



baud sinuatiis, intus subinteger (mitmtissiine creiiulatus) ; cardi- 

 nalis valde latus. Nates acutae. Lunula liaud sculpta, prot'unde 

 circumscripta : area subiaconspicua. Deutes antici permulti ; 

 postici perpauci. Fossa cartilaginis angusta, obliqua. — Large, 

 strong, oblique, ovate, scarcely ventricose, smootliish or with 

 coarse incremental wrinkles in front, very inequilateral, not colour- 

 rayed, silvery-white within, simply rounded in front, rotuudately 

 angulated below behind. Front dorsal edge convex, not remark- 

 ably sloping ; hinder slope decided, straightish or subretuse, 

 siuuated by the profound concavity which defines the lunule. 

 Ventral margin arcuated, devoid of a sinus, not distinctly crenu- 

 lated within, yet most minutely so at the outer edge. Beaks 

 acute, not much elevated. Hinge-margin very broad : front teeth 

 very numerous ; hinder ones very few : cartilage-pit narrow, 

 moderately slantmg. — I am indebted for the recognition of this 

 species to M. Chenu, who having delineated the type for his beau- 

 tiful ' Manuel,' kindly forwarded me the unpubhshed woodcut. 

 The epidermis ranges from shining olivaceous-yellow to dark ashy- 

 olive. 



24. N. CoMiNGii, Hinds, f. 117. — T. ovaK-elHptica, baud 

 ventricosa, laevigata, lineis incrementi subpliciforraibus tantum 

 ornata, cute nitidissima pallide ohvaceo-virente induta. Extre- 

 mitas antica subattenuate rotundata, superne subemarginata; 

 postica rotundato-acuminata, et longior quam in Nucidis aliis. 

 Margo ventralis integer, fere semicircularis, postice subsinuatus. 

 Lunula parva, lanceolata, planulata. Area permagna, prominens, 

 retusioue sulciformi circumscripta. — Oval-elhptic, only subveutri- 

 cose, everywhere smooth, except for the subpliciform wrinkles of 

 increase, with a jjohshed pale greenish-ohve epidermis. Anterior 

 extremity somewhat tapering, rounded, subemarginate above, front 

 dorsal slope convex and nearly horizontal. Posterior side long for 

 the genus, rotundately peaked, the peak subcentral, the somewhat 

 ret use dorsal slope not being abrupt as usual. Ventral margin 

 entire, almost semicircular, with a shght refusion near its posterior 

 extremity. Lunule small, lanceolate, flatly impressed. Lozenge 

 large, prominent, well and concavely defined in the adult. Teeth 

 usually six and eighteen. 



25. N. Grayi, lyOrhigny, f. 126.— T. ovalis, longitudine lati- 

 tudinem multo superante, subventricosa, Isevis, cute nitidissima 

 olivaceo-virente (rarius oKvaceo-fuscescente) induta, antice sub- 

 attenuate, postice subangulatim, rotundata. Latus posticum baud 

 perbreve. Margo dorsalis antice couvexus, prope nates baud emi- 



