COXCHOLOGICAL MEMORANDA, 



[From I'voceeiiings Cal. Acad. Xat. Sci., .Sept. 4, 1871.] 



Mr. Stearns read the folloAving , 



On the Habitat and Distribution of the West American Species 

 of Cyprseidee, Triviidse and Amphiperasidse, 



Being correct/oils to Mr. Roberts^ Catalogues * of the "Porcellunida^' mid 



Ampliiperasida. 



BY ROBERT E. C. STEARNS. 



Mr. Roberts' Catalogues — if the West American species are any criterion — 

 throw no new light upon the distribution of the species enumerated therein ; 

 neither are the more accurate statements of authors more reliable in this respect 

 than Reeve, Sowerby and Kiener — whose indetiuiteuess and errors lie has blindly 

 repeated therein — referred to or considered. 



The remarks of Mr. J. IT. Redtield. on page 88, Volume V. of American 

 Journal of Conchology, on the sins of the late Mr. Reeve in this respect, apjily to 

 Mr. Roberts, for it is not too much to expect, or even demand of an American 

 writer, that he should be aware of and correct errors of the kind referred to 

 herein, at least, when said errors occur in connection with American species. 

 Mr. Redfield says: "The fi'cquent errors of statement in regard to habitat are, 

 perhaps, the most mischievous fault that can be brought against the work, for 

 on them are liable to be based erroneous conclusions in regard to the important 

 questions of geographical distribution, and of permanence in species." 



If the species, the habitat of which is corrected by me in this paper, were 

 from remote localities or little known, it would be less cause of surprise ; but 

 the Check-Lists of the Smithsonian Ii]slitution, Carpenter's Reports to the 

 British Association, Dr. Cooper's Geographical Catalogue of the Mollusca, 

 published in connection with the work of the Geological Survey of California, 

 and sundry local lists of my own in the Proceedings of the California 

 Academy of Natural Sciences, were equally as accessible to Mr. Roberts as 

 the monographs from which the catalogues were compiled. 



* 'I'he Catalogues referred to were published in connection with the "Am. 

 Jour, of Conch.," Vol. V, Part III. 



