Marine Shells from Trinidad. 51 
Cardium eburniferum, Guppy. Pl. VII. fig. 3. 
Shell a little angularly suboval, moderately tumid: externally 
marked with irregular orange-brown spots, and adorned with 
thirty-five narrow imbricated ribs closely covered towards the 
margins of the shell with numerous porcellaneous semitubular 
tubercles, which are thicker anteriorly ; posterior edge nearly 
straight, strongly serrate. Hinge-teeth |5—, strong. Interior 
salmon-colour, growing white towards the strongly dentate 
margins, which are yellowish. Height 52 millims., length 45, 
thickness 40. 
Hab. South coast of Trinidad (7. W. Carr). Found abun- 
dantly at Grenada. 
Cardium haitense, Sowerby, Quart. Journ. Geol. Soc. 
vol. vi. p. 52, pl. x. f. 11. 
An oblique subovate shell, with 20-24 radiating, nodose, 
rather square ribs wider than thei finely crenate interstices. 
Allied to C. subovale, Brod. 
This was originally described by Sowerby as a fossil from 
Haiti; but I have dredged two small examples of it in the 
Gulf of Paria. 
Arca centrota, Guppy, Proc. Scientific Assoc. of Trinidad, 
ps iva Mec: b860).o PE VAL, eid: 
This species was described as a fossil; but I have since 
ascertained that it is likewise living on our coasts, having been 
collected by myself on the shores of the Gulf of Paria, and 
by Mr. Carr on the south coast of Trimidad. Its umbones 
are often pink or red, which colour is visible inside as well as 
outside ; and the shell has a hairy epidermis, generally worn 
off at the umbones. Height 17 millims., length 24. 
The following is the original description :—“ Transversely 
subrhomboidal, with a strong wide carination running from 
the umbo to the posterior angle; ornamented with many 
(36-38) squamosely nodose radiating ribs, each with a fine 
subsidiary thread-like rib in the narrow interstice ; anterior 
margin short, rounded; posterior margin strongly sinuate, 
angulate above with the hinge-line, and forming a more rounded 
angle with the strongly crenate lower margin. Hinge-teeth 
small in the middle of the straight hinge, but becoming larger 
and diverging considerably towards the angles; ligamental 
area more or less grooved, especially anteriorly.” 
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