352 



REPORT — 1856. 



The following shells are quoted from San PfcDfto i— 



Sanguinolaria Nuttalli. 

 *Semele rubrotincta. 

 *Tellina secta. 



Mactra nasuta. 

 *Venus Nuttalli. 



fructifraga. 



— — Califoruiensis. 



*Tapes straminea. 



gracilis. 



*Diplodonta orbella. 



Cardium cruentatura. 

 *Chama exogyra. 

 *Bulla nebulosa. 

 fAcmcea mesoleuca. 



*Acinffia'scabra. 

 •Scurria mitra. 

 *Trochus mcestus. 

 fCrepidula incurva. 

 fCalvptrsea spinosa. 

 fLitorina ? fasciata. 

 Oliva biplicata. 



The following shells are quoted from Guaymas. They all belong to the 

 Southern fauna, except Bulla nebulosa and Venus straminea, which last be- 

 longs to that of Upper California. It may be a wrong determination for the 

 not dissimilar Tapes histrionica* 



Pectunculus giganteus. 

 Pecten circularis. 



*Bulla nebulosa. 



Lophyrus laevigatas, 



albolineatus. 



fAcmaea mesoleuca. 

 1'Neritina picta. 

 fNerita Bernhardi. 



Periploma planiuscula. 

 fPetricola robusta. 

 t Venus Columbiensis. 



Californiensis. 



* straminea. 



fTapes grata. 



Cardita Californica. 



Chama f. Mexicana. 



Cardium elatum. 



Omphalius rugosns. 



Terebra variegata. 



Conus ferrugatus. 



t regularis. 



fNatiea maroccana. 



bifasciata. 



Fusus pallidas. 



lignarius. 



The following shells are quoted from San Juan ; many others are pro- 

 bably from the same place, but are assigned by error to the Straits of the 

 same name in Oregon. 



fTerebra fulgurata. 

 fConus princeps. 

 fOniscia tuberculosa. 

 fCassis coarctata. 

 Olivella intorta. 



fSanguinolaria purpurea. 



Tellina gemma. 

 *Donax Californicus. 



Bulimus pallidior. 

 fRadius variabilis. 



fOlivella tergina. 



? eburnea. 



Monoceros tuberculatum, 

 t Purpura muricata. 

 fMurex plicatus. 



The following are quoted from La Paz 



Thracia plicata. 

 fMactra elegans. 



Venus reticulata. 

 fDione Chionasa. 

 fArtemis gigantea. 



Petricola dactylus. 

 tLucina punctata. 



Modiola capax. 

 1'Tsognomon Chemnitzianum. 



Lima tetrica. 



Pecten nodosus. 



dentatus. 



Spondylus, sp. 



fOstrea Cumingiana. 

 fCancellaria obesa. 



t solida. 



t cassidiformis. 



Sigaretus debilis. 

 fStrombus gracilior. 

 fOliva porphyria. 



t spleudidula. 



fPurpura patula. 



* emarginata. 



t biserialis. 



t kiosquiformis. 



fMurex bicolor. 



78. A mere glance at the general Table, contrasting the species on each 

 side of the double central dividing line, especially leaving out of view the un- 

 certain column of Lower California, will satisfy the inquirer of the marked 

 and rapid separation between the two faunas of California-proper and the 

 Gulf. Tbe actual difference is, however, much greater than the apparent, 

 since the name of a species occurs in a column if only one specimen has been 

 obtained, whether or not it were living there ; or if living, whether it were 

 an habitual resident or a straggler. For it will be observed that our present 

 lists are much in the condition of those of British shells, before the labours 

 of the dredging naturalists of our own day ; when a W. Indian shell was duly 





