•1 _ 



"been able to obtain soeeinens of it for -"^n ^ariL;on." ( Dall, 1890) 



'Jype losalit:; .- Bor/den, Jaraaica. 



The shell is small, well-inf latel, moderately inequilateral, 

 elongate, rostrate; left valve slightly smaller than the right; 

 abruptly roimded anteriorly, posteriorly the margin sloping above, 

 obliquely subtnu-ic belo?/, the angle betv/een the two portions, 



obt se and subrouiide "^ to roiuided; bas^ rc.-tly arciiate, sli--^htly 

 emarginated posteriorly, the postoro-ventral arg-le sharp and 

 less than 90 ; posterior carina well-define ^1, sharp or subrou.d- 

 ■e^ , ventrslly the sn.rfaee of the shell slightl^ depressed in front 

 of the carina. 



ReFarlrs. - 0_. serioea is very rirolific, being the most abund- 

 ant Qorbula . It is recognized by its somewhe.t elongate outline, 

 fine, but strong ooneentric sculpture aiid weaJc, fine radials. 

 The radials are never prominent and may be entirely absent. 3ome 

 of the valves are higher than the tr T)ical form. 



Ball has placed in synonymy Hie fossil fbrms which Guppy 

 deteDnainel as the recent "3. cubaniana d'Orbigny (1), but ao-oarent- 



(1). In de la Safrra, -ist. )h s., polit . et natur., f^.e I'lle 



de 3uba, Koilusques, vol. r„ ^^. '^^'7^ -n . r% fi^s. 51-54, l^^n:^ 



ly Gup^y reported that species on! " from the Pliocene of Trini- 

 dad and if the Trinidad form i:' sericea that lor>-Ti-^^- ■■<:<! horizon 



