or SAXTO DOMmGO. 



253 



LITIIOPIIAGUS. Muhlf. . ; ' 



L. corrugatns. Phil., sp. . .■ 



Modiolo corrugata. Philippi Abbild., Vol. II., p. 147, pi. 1, lig. 1. . ' 



Lithodomus, id. Eve. Icon. sp. 1. - • 



Lithodomus Antillarmn. D'Orb,, Lea Sagra, pi. 28, fig. 13, 13. 

 Not L. Antillarum. Philippi. 



Found boring coral at Cevico and elsewhere at the extreme top of the formation. 

 I have never found it in the shales of a lower horizon. , . . 



L. n. s. 



A second species, about an inch long, apparently nearly cylindrical, regularly 

 rounded at the posterior end and without transverse corrugations, occurs in the corals 

 west of Santiago. I have never succeeded in breaking it out in sufficiently perfect 

 condition for description. 



AVICULA. Brng., Lam. , ' . 



A. inornata. Gabb, n. s. 



Shell small, oblique, convex ; anterior ear small, triangular, posterior moderately long, acuminate ; surface 

 smooth, without ornament. Length 1 inch. 



In shape and in the character of its ears, this shell is nearest to *A. Tarentina, ex- 

 cept that it is 3iot so produced below. The anterior margin is also a little less convex 

 immediately below the ear. There is a similar shell in the Museum of the Philadelphia 

 Academy, without a name, labelled " Coast of Brazil." It is probably this species, 

 but I cannot find it in any of the books. From A, cornea, Rve., it can be distin- 

 guished by its smaller posterior ear, its less obliquity and its more convex form. 



PINNA. Linn. 



P. sp. ? 



A single little fragment, only sufficient to recognize the genus. 



ARCA. Linn. 



A. (Anadara) grandis. Brod. and Sby., Zool. Jour., Vol, IV, 

 A. Patricid. Sby., Quart. Jour., Vol. VI., p. 52, 



Area, very like grandis, Moore, Quart. Jour., Vol. IX. 



In hia description, Sowerby dwells so carefully on the difl'erence between the fossil 

 and Panama shell that I have taken the pains to make a very careful comparison 

 between the two. The species is exceedingly common, and I have it of all sizes fi'om 

 that of a pea to six inches in length. The base is not more convex than the recent 

 shell ; there is no difference in the hinge more than occurs between individuals of 

 different ages ; and on carefully counting the ribs in a series of each, I can find no 

 ditference in theii' number, form or arrangement. 



A. (Anadara) consobrina. Sby., Quart. Jour., Vol. VI., p. 52, pi. 10, lig. 12. 

 Anomalocordia Floridana. Con. Am, Jour. Conch., Vol. V., p. 108, pi. 13, fig. 12. 



Inhere can be no doubt of the abov€ synonymy since I have used Ivli-. Conrad's 

 A. p. s. — VOL. XV. OL. 



