436 B. J. L. Guppy — West Indian Tertiary Fossils. 



and posterior angles rounded ; zoned with broad dark bands, and 

 finely radiately striate; margins crenate-dentate. 



Pliocene, Trinidad. Eemarkable for its resemblance to B. faba- 

 gella. It is more equilateral than that species, and not so high 

 relatively to its length. 



Venus Blandiana, n. sp., PL XVII. Fig. 8. 



Suborbicular, subequilateral, moderately convex, adorned with 

 numerous equidistant concentric lamella3, between each of which 

 there are about seven or eight concentric stri^ ; somewhat angulate in 

 front and subtruncate behind; margins crenate. Lunule smooth, 

 impressed. Posterior dorsal area not defined, striate continuously 

 with the lamellse of the disk. Umbones small. Cardinal teeth two 

 under the lunule ; lateral tooth one, nearly halfway down the posterior 

 slope. 



Eeferred to hitherto in papers on West Indian fossils as Venus 

 rugosa, var., to young specimens of which species it bears a some- 

 what close resemblance. The Jamaican examples are smaller than 

 those from Haiti. A specimen in the British Museum from the 

 latter place is labelled V. circinaria, but it is not Cytlierea circinata, 

 nor even nearly allied to it. 



When describing GytJierea juncea from Cumana, I omitted to point 

 out the close kinship between that fossil and G. circinata. 



Chama involuta, n. sp., PL XVII. Pig. 5. 



Left (attached) valve deep internally, very convex externally, 

 often spiral, completing a turn and a half, covered externally with 

 distant large foliaceous scales more or less erect, between which are 

 small irregular diverging granose ridges. Eight valve patulous, 

 ornamented with numerous close concentric sinuous foliaceous 

 laminse. Umbones large, prominent, spiral. Margin and laminar 

 cardinal tooth crenate. 



Mr. Vendryes suggested that this might be a Diceras ; but I see 

 no ground for referring it to that genus. It is certainly a very spiral 

 Chama; but otherwise its characters are in all respects those of the 

 genus. It is apparently always attached by the umbo of the left 

 valve, and the place of attachment is generally marked by the 

 remains or impressions of the septa of corals. It has some re- 

 semblance to a recent species found in the West Indies, which, if I 

 have identified it correctly, is Gh. ruderalis, Lam. ; but besides other 

 considerable differences, the latter is always attached by its right 

 valve. 



Plicatula vexillata, n. sp., PL XVII. Pig. 7. 



Inequivalve, irregularly fanshaped ; valves, usually with the disk 

 almost smooth, adorned towards the margin by seven or eight stout 

 obtuse radiating ribs, along each of which are disposed a few lines of 

 reddish brown (probably red when alive), and between which are 

 some distant almost foliaceous concentric striae of growth. Longest 

 diameter about 17 mill. 



Very near to P. ramosa, Lam. Florida. 



