ON MOLLUSCA OP THE WEST COAST OF NORTH AMERICA. S5X 



chances of error. We shall then know, and not satisfactorily till then, where 

 and how the two great faunas of West N. America, both of which go loosely 

 by the name of " Californian," find their separation. 



The imperfect data of the Pacific coast of Lower California only furnish 

 us with Palliobranchs, 1 ; Lamellibranchs, 60 ; ordinary Gasteropods, 49 ; 

 Toxifera, 7; Proboscidifera, 20: total 137 species. As the localities are so 

 far from being satisfactorily established, an exact analysis of them will not 

 here be attempted : but the fauna of each spot will be given entire so far as 

 known, both on the Pacific shores and in the Gulf. The species marked * 

 belong to the Californian type ; those marked f to the Panamic. 



The following list contains the known shells of San Diego : — 



Pholadidea ovoidea. 



* penita. 



*Parapholas Califomica. 



Saxicava Pholadis. 

 *Petricola Californica. 

 *Saxidomus Nuttalli. 

 *Platyodon cancellatus. 



*Sphaenia Californica. 

 *Lyonsia Californica. 



Periploma argentaria. 

 *Solecurtus subteres. 

 * Californianus. 



Sanguinolaria Nuttalli. 



Psammobia Pacifica. 

 *Tellina nasuta. 

 * — — secta. 



■ pura. 



vicina. 



Cumingia Califomica. 

 *Semele decisa. 



flavescens. 



* rubrolineata. 



*Donax Californicus. 

 *Venus Nuttalli. 

 * Califomiana. 



excavata. 



dispar. 



fluctifraga. 



*Tapes straminea. 

 *Trigona crassatelloides. 

 *Cardium Nuttalli. 



* Californiense. 



* substriatum. 



t elatum. 



luteolabrum. 



Cypricardia Californica. 

 *Chama exogyra. 



pellucida. 



*Diplodonta orbella. 

 tLucina punctata. 



bella. 



Californica. 



Nuttalh. 



tLithophagus atteuuatus. 

 •Mytdus Californianus. 



Modiola capax. 



Area pemoides. 

 *Pecten latiauritus. 



Peeten floridus. 



purpuratus. 



tOstrea conchaphila. 

 t plumula. 



Hinnites giganteus. 

 *Helix tudiculata. 

 * Kellettii. 



Bulimus pallidior. 

 fMelampus olivaceus. 



Haminea vesicula. 

 *Bu]la nebulosa. 



virescens. 



longinqua. 



Tornatina inculta. 



Mopalia Blainvillei. 

 *Acm8ea patina. 



* persona. 



* grandis. 



* spectrum. 



* scabra. 



fascicularis. 



*Fissurella volcano. 

 ♦Haliotis Californiensis. 



* Cracherodii. 



* splendens. 



*Osilinus ater. 

 *TrGchus iilosus. 

 *Omphalius aureotinctus. 



* brunneus. 



*Phasianella compta. 

 fTurbo Fokkesii. 

 fPetaloconchus macrophragma. 

 *Cerithidea sacrata. 



albonodosa. 



pullata. 



tNatica uber. 



Ranella triquetra. 



muriciformis. 



Californica. 



t[01iva splendidula]. 



Purpura emarginata. 



Columbella carinata. 



Californica. 



fNassa luteostoma. 



fossata. 



t tegula. 



Murex Belcheri, 



