lIcUx (i>i[ioyt<(i i II ('(iliforniii. 13o 



between any of the places Mhei'e it had ])reviously been found 

 and that part of California to which Prof. Forbes credits it, nj) 

 to the date of said credit, or, rather, tlie date of the " Herald" 

 collection. Since then, during the time which embraces the 

 "great emigration" following the discovery of gold in Cali- 

 fornia in 1849. that part of the coast of California has had but 

 little if any direct contact with vessels from ports in countries 

 where //. aspersa exists. Prior to 1849, the coastwise ti-affic 

 was very insignificant, and the foreign commerce consisted only 

 of the few vessels engaged in the hide and tallow trade, and the 

 whalers; therefoi'e its introduction by such means is altogether 

 improbable. 



For the very reason that Forbes was intimately familiar with 

 aspersa in all its varied asjiects. — I believe he was led to credit it 

 to the West coast through the striking resemblance which occa- 

 sional sjiecimens of Tryoni, Steanisiana, and Kellettii bear to 

 occasional specimens of aspersa; not typical or average specimens, 

 but extreme, unusual, but occasional individuals. 



J have before me now a specimen which connects extremes of 

 Kellettii and Stearnsiana; it is strikingly like an extreme speci- 

 men of aspersa which is also before me. I have likewise, speci- 

 mens of ]"ather dark colored H. Tryoni. which strikingly resem- 

 ble a light colored dwarf aspersa. 



If the California specimens referred to in this comparison were 

 placed Avithin a region where aspersa is abundant, they would at 

 once be regarded as dwarf varieties or aberrant individuals of 

 that species. If the specimen of aspersa referred to was placed 

 within the territory of either Tryoni, Kellettii. or Stearnsiana, it 

 would be considered a variety of one or the other according to 

 the area within which it was placed. 



Having possessed, seen, and noticed at various times a great 

 number of all of the species above named, and observed their 

 range of variation and approximation to other forms, I regard 

 this hypothesis, as to Forbes's H. aspersa in "Sta Barbara," in 

 connection with the other related points presented, as a reason- 

 ably satisfactory solution of the matter; as furnishing a better 

 basis for Forbes's credit of aspersa to this coast, at that time, 

 than any other that is left us to choose from, viz., that the shell 

 he had before him was a veritable aspersa; — or that a true as- 



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