new Species of dementia. Gl 



strife are more prominent than others. Lunule cordate, 

 faintly circumscribed and nearly Hat, but not impressed ; 

 escutcheon not defined, but its ligamental edges slightly 

 raised; ligament completely sunk, but conspicuous and 

 rather long. 



Interior smooth, white, opaque ; pallial sinus ascending, 

 angular, bounded by straight lines, not reaching to the middle 

 of the valve. Posterior adductor scar larger than the 

 anterior. Hinge-plate well developed and prolonged at each 

 end, with three cardinal teeth in each valve, the first in the 

 right being tall and prominent and the third deeply and 

 widely bifid ; in the left the first and second are united at 

 the top, the third is distant, long, laminar, and highest at its 

 posterior end. 



Testa paulo major (59 X 44 mm.), satis valida, haud tenui, oblonga, 

 obliquissima, umbouibus adeo provectis ut linea de vertice pen- 

 dens quatuor partes longitudiuis a quinta desecat ; latere antico 

 attenuate*, propter marginis veatralis acclivitatem ; latere postico 

 lato et subtruncato, declivitate dorsali arcuata. 



Valvis inflatis, albidis, striis concentricis densis irregularibus sculptis, 

 non undulatis, quanquam striae complures inter ceteras exstant. 

 Lunula cordata, linea indistincta circumscripta, fere plana sed non 

 impressa ; area non definita, sed marginibus ligamentum contin- 

 gentibus elevatis ; ligamento elongato, profundato, sed per rimam 

 conspicuo. 



Pagina interna albida, opaca ; sinu pallii ascendente, lineis rectis 

 cincto, apice acuto, medio valvae non porrigente. Yestigio mus- 

 culi posterioris quam anterioris majore. Lamina cardinali exserta 

 et utrimque producta, dentibus tribuscardinalibusmunita, quorum 

 in valva dextra primus altus et prominens est, tertius late et 

 profunda bitidus ; in valva sinistra dentibus primo et secuudo 

 ad verticibus conjunctis, tertio longo, remoto, angusto, ad finem 

 posticam altiori. 



Since the above was written, I have ascertained from 

 Dr. L. Germain that C. vatheleti has not yet been figured, 

 and he has been good enough to send me one of the types in 

 the Museum d'flistoire Naturelle of Paris, in order that it 

 may be figured and compared with C. ohliqua. I therefore 

 take this opportunity of describing C. vatheleti in English. 



Shell rather la«ge (66x56 mm.), fairly strong, but not 

 quite so solid as C. obliqua, oblong-ovate, and almost sub- 

 quadrate, very oblique, with prominent umbones, which are 

 placed very far forward ; anterior side short and rounded, 

 ventral side expanded into a semicircular curve and sloping 

 up to meet the postero-dorsal border, so that the greatest 

 length of the shell is across the muscular scars ; postero- 



