

* 



60 



CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD 



Chione paraensis White. 



Venus ( Chione) paraensis White, Arch, do Museu Nac. do Rio de Janeiro, vol. VII, pp. 94-95, 

 pi. V, figs. 34, 35, 1887. 



White's original description .— " Shell rather small, gibbous, transversely sub- 

 elliptical in marginal outline; lunule moderately large, cordiform, prominent, 

 distinctly grooved by a narrow, sharply impressed groove; escutcheon long, 

 lanceolate, concave from side to side, bounded on each side by a distinct ridge 

 which extends from the beak by a gentle outward curve, to the posterior border; 

 umbones slightly elevated ; beaks small, closely incurved upon the cardinal mar- 

 gin and turned forward ; cardinal margin broadly and regularly convex ; anterior 

 and posterior margins regularly and almost equally rounded; basal margin 

 broadly and regularly convex ; cardinal teeth well developed ; sublunular tooth 

 comparatively strong. Surface marked by numerous sharply raised, finely 

 crenulate, concentric lamellae which cover the whole surface including the lunule 

 but not including the narrow escutcheon. These lamellae consist of merely 

 close-set, raised striae upon the beaks, but they become stronger and wider apart 

 towards the free margins. 



"Length 21 millimeters; height from base to umbones 18 millimeters. 

 Rio Piabas, State of Para, Brazil. 



)) 



Chione paraensis White 



Figu 



A varietal form of Dr. White's Chione paraensis is rather common in the 

 Soldado fauna. It differs from the type in its less convex form. 



Length of largest shell 20, height 15 mm. 



Locality.— Bed No. 2, Soldado Rock, Gulf of Paria, near the Serpent's Mouth. 



Geological horizon. — Midway Eocene. Equivalent to the Midway of Alabama 

 and that of the Maria Farinha beds, State of Pernambuco, Brazil. 



Genus VENERUPIS Lamarck, 1818. 



Venerupis Lamarck, An. s. Vert., V, p. 506. 



Man 



Moll 



Not 



Venerupts Fischer, Man, de Conchyl., p. 1087, 1887. 



Irus Herrmannsen, Ind. Gen. Mai., II, p. 684. Not Irus of Oken. Lehrb. der 



848, 1815. 

 Venerupis atlantica 



Figur 



» 



Description.— Shell characterized by its very striking sculpture which consists 

 of (a) sharp-edged, nearly regular and equidistant, thin, erect, concentric lamellae, 

 which are more elevated at the upper posterior margin ; (b) radiating striae which 



very fine, close, nearly regular, and ornament the surface of the shell between 



hinge lacking 



the erect ridge-like lamellae which the striae do not 



Height of fragment 10 mm 



Remarks.— This is the first species of Venerupis ever found in the fossiliferous 

 beds of the eastern coasts of the Americas. 



The genus now lives in all the European seas, and the Indian and the Pacific 



Oceans 



It is not now represented in the Atlantic 



