FOSSIL SHELLS. 285 



10. Mytilus ovalis, Lam. One specimen. 



11. Paphia DONACIA^ Young. Eare. 



No. 1. Darwin did not find this species among tlie recent upraised shells near Valparaiso. 

 It is a common living species on that part of the coast of Chile, where it has heen dredged up 

 from a depth of ten to twenty fathoms. No. 2 is recent on the coast of Peru; No. 4, recent at 

 Valparaiso; No. 5, ditto ; No. 6, recent at Coquimho and Copiapo; No. T, living on the coasts 

 of Chile and Peru ; No. 8, living at Valparaiso; No. 9, living at Copiapo ; No. 10, living on 

 the coast of Peru. No. 11 : Darwin says, that about Quintero there are immense accumula- 

 tions of this species, packed in sandy earth. It lives north and south of Valparaiso, inhabiting 

 sand-banks at the level of the lowest tides. 



Tertiary Shells of Chile. 



In the collection I find three shells which are probably extinct species, as they differ widely 

 from any recent shells of the Pacific coast that we have in our collections or are described in 

 scientific j)ublications. They have no resemblance to Eocene species; but, from their corre- 

 spondence with Miocene forms, I have scarcely a doubt that they will prove to be members of 

 that formation. I have traced Miocene deposits from Columbia river, in Oregon, to San Diego, 

 in California, by means of fossil shells collected by Townsend, Dana, Lieut. Blake, Dr. Heer- 

 mann, and Dr. Leconte ; and no doubt the same formation, or synchronous deposits, may yet be 

 found at intervals from San Diego to Cape Horn, at greater or less distances from the coast, and 

 sometimes, as in California, bordering the sea. 



PEENA. 



Plate XLII, Fig. 7. 



P. CHILENSIS, Conrad. Oblong-subquadrate ; anterior hinge extremity somewhat rostrated; 

 anterior margin rectilinear ; hinge oblique, and furnished with about fifteen cardinal teeth ; 

 posterior margin and basal margin rounded ; muscular impression oblong ; subovate, very 

 large. • 



Locality. Caldera, Chile. 



This is a cast of a very large species, allied to P. maxillata of the Virginia Miocene, and 

 measures ten inches from hinge to base. The muscular impression is remarkable for its size ; 

 measuring 4^ inches in length, and its greatest breadth three inches. 



OSTEEA, Linn. 



0. COPIAPINA, Conrad. Upper valve obliquely oblong-oval, somewhat curved, ventricose, with 

 very broad, not elevated, irregular radiating undulations ; cartilage depression profoundly di- 

 lated ; beak not prominent, submargins entire ; muscular impression profoundly elongated^ 

 falcate; cavity capacious. 



Locality. Line of Copiapo railroad. 



This is a large species, measuring from beak to base seven inches ; from anterior to posterior 

 extremities_, eight and a quarter inches. I have not seen the lower valve, but suppose it to be 

 not very different from the opposite one. There are some large Balani attached to it, resem- 

 bling a Miocene species of Virginia; but not being in good condition, it remains undetermined. 

 These shells are imbedded in a brown quartzose sand, and were found at an elevation of four 

 hundred feet above the sea. 



