346 



REPORT — 1856. 



under a host of names to the peninsula, and even straggles into the Gulf. 

 Scurria mitra, Osilinus ater and Omphalius mcestus reach from Sitcha to 

 Lower California, and Acmcea persona sparingly enters the Gulf; while the 

 ubiquitous Saxicava, one species probably under a variety of names and 

 forms, appears, like man and dog, to adapt itself to every variety of climate, 

 and to reappear in every well-searched fauna, boasting also of being one of 

 the most ancient types now living on the surface of our globe. The 

 Litorina aspera and Callopoma Jluctuatum, quoted on the authority of 

 Barclay, are so essentially tropical, that we may be allowed to suspend our 

 judgment before we receive them into the fauna. 



74. The Oregon shells belong, in the main, to the Californian type, but 

 present, thus far, peculiai'ities which demand a separate study. The total 



number known are 14*4; = 



Of these have, in addition, been! .„ 



found only in Upper California j ~" 

 „ also in Lower California 12= 



Bivalves. 



49 

 6 

 5 



uSS. T-ifera. 



72 

 9 

 6 



Probosci- 

 difera. 



22 

 1 

 1 



The following — Crenella discrepans, Trichotropis borealis and Bela ?tur- 

 ricula, are European forms. The following are the principal sea shells as 

 yet peculiar : — 



Terebratula pulvinata and canrena. 



Panopsea generosa. 



Solen sicarius. 



Venus calcarea and ampliata. 



Cardium blandum. 



Pecten cauriaus, hericeus and Town- 



sendi. 

 Placunanomia alope and cepio. 

 Chitonidae dentiens and lignosus. 

 Callochiton interstinctus. 

 Mopalia vespertina. 

 Chiton muscosus. 



Katherina Douglasiae. 

 Punctiu'ella cucullata and galeata. 

 Litorina lepida and scutellata. 

 Lacuna carinata. 

 Cerithiopsis filosa. 

 Lunatia caurina, herculsea, algida. 

 Purpiura ostrina and lagena. 

 Columbella gausapata (the mostnorth- 



erly species of the genus.) 

 Nassa mendica. 

 Trophon Orpheus and corrugatus. 



75. A comparison of the shells of the N. W. and S. W. shores of America 

 offers certain remarkable points of identity. The standard limpet of the 

 northern seas is Acmcea patina. On reaching the Gulf, it is replaced by 

 A. mesoleuca, which probably extends through the Panamic province. But 

 when we approach Chili, we again find the A. patina in D'Orbigny's collec- 

 tions, and it is figured by Mr. Reeve as though brought by Cuming. Indeed 

 if the Chilian and Californian specimens were mixed, it would be impossible 

 to separate them by the shells alone. It is true that Philippi, recognizing 

 some of Eschscholtz's Sitchian species as southern forms, accuses the latter of 

 mixing the labels ; but probably they occur in each fauna. The Scurria 

 mitra also, though somewhat more local, is a very abundant shell on both 

 coasts. The Acmcea cassis of Eschscholtz appears only a northern reproduc- 

 tion of the Patagonian Patella deaurata, Gmel. The Fissurrella violascens, 

 Esch., is assigned by him to the south, to which in type it belongs ; but it 

 has some claims on the northern fauna for admission. The Bullia ampullacea, 

 Midd., is essentially a southern type, especially abounding in peninsulas ; of 

 its specific relations we are not yet able to judge. The Natica caurina of 

 Gould, appears a geographical creation for the southern N. impervia of 

 Philippi ; while of the Oregonian Scalaria, Dr. Gould confesses theit he has 



