102 PALEONTOLOGY OF CALIFORNIA. 



ARCA, Linn. A. sulcicosta, Gabb. 



Area sulcicosta, Gabb ; Pal. Cal., Vol. 2, p. 31, pi. 9, fig. 53. 

 Pliocene, Santa Rosa. 



A. MICRODONTA, Con. 



Area microdonta, Con. ; P. R. R. Rep., Vol. 5, p. 323, pi. 3, fig. 29. 



A. canalis, Con. ; P. R. R. Rep., Vol. 6, p. 72, pi. 2, fig. 8. 



A. trilineata, Con. ; P. R. R. Rep., Vol. 6, p. 72, pi. 2, fig. 9. 



? A. devincta, Con. ; q. v. Should these prove to be the same, devincta being 



the earliest name given, will have to stand as the name of the species. 

 Miocene, Martinez, Griswold's, Santa Barbara, near Buena Vista Lake, El 



Toro and Najohui Ranches (Oregon ? — devincta) ; Pliocene, San Fernando. 



AXINJEA, Poli. A. patula, Con., sp. 



Pectuncidus patulus, Con.; Wilkes's Exped., p. 726, pi. 18, fig. 8. 



Not P. patulus, Con. ; Jour. Conch, 1865, p. 153 (=: Lucina borealis). 



Axina'a Barbarensis, Con. ; P. R. R. Rep., Vol. 6, p. 73, pi. 3, fig. 11. 



Id., Con. ; P. R. R. Rep., Vol. 7, p. 194, pi. 6, fig. 3. 



Miocene, Astoria, San Pablo, Santa Barbara, Martinez ; Pliocene, Santa Rosa. 



NUCULA, Lam. S. Gen. Acila, II. & A. Ad. N. (A.) Castrensis, 

 Hinds, sp.* 



Nucula C'astrensis, Hinds; Proc. Zool. Soc, 1843, p. 98. 

 Id., Hds. ; Voy. Sulphur, p. 61, pi. 17, fig. 5. 



N. (Acila) Castrensis, H. & A. Ad., Genera. Rec. Moll., Vol. 2, p. 545. 

 Nucula divaricata, Con. ; "Wilkes's Exped., p. 725', pi. 18, fig. 6. 

 Nucula divaricata, Con. Am. Jour. Sci., 1848, p. 432, fig. 1. 

 Nucula decisa, Con.; P. R. R. Rep., Vol. 5, p. 322, pi. 3, fig. 19. 

 N. Conradi, Meek ; Smithsonian Check List. 



Miocene, Astoria, Martinez; Pliocene, San Fernando; Post-Pliocene, Santa 

 Barbara, San Pedro, San Diego. Living. 



* It has been claimed that this is the same as an English crag species, N. Cob- 

 boldia. I hardly think it necessary to attempt a serious refutation of the idea. It 

 would be contrary to all received notions of geographical distribution, to find here 

 an isolated species from an entirely distinct fauna, and out of another ocean. Tho 

 mistake has arisen from the close resemblance that exists between all the species 

 of this sub-genus ; a similar confusion having been created by Mr. Conrad between 

 the present shell, and an allied form from the cretaceous beds of California. 



