THE NAUTILUS. 119 



method of identifying Risso's species by means of Pfeiffer's identifi- 

 cations of Draparnaud's figures, as opposed to the method by the 

 study of Risso's own descriptions. 



In my opinion, any sound work based upon Risso must begin with 

 a study of his descriptions, specimens in hand. In the case of non"- 

 marine forms, the task has been materially lightened by Bourguignat, 

 wiio examined and reported upon Risso's collection; but even with 

 this, it is safest to check up all points with the shells and descriptions 

 themselves. 



In the matter of Alsea Jeffreys, a few words may not be amiss. I 

 hold that when an author distinctly indicates a certain group by his 

 diagnosis, the mere inclusion of some heterogeneous species should not 

 be allowed to totally pervert his intention. This is common law, 

 and good law too. Now Jeffreys defines Alsea as having short 

 lamellae in the mouth (making no provision for toothless forms in 

 his diagnosis); and he expressly states that Alsea is separated from 

 Vertigo because the shell is dextral (the type of Vertigo being sinis- 

 tral). 



Now there are still authors who hold that the dextral Vertigines 

 need a subgeneric or sectional name, and from the time of Gray 

 (1847) to the last Catalog of Westerlund (1890) the name Alsea, 

 with the type antivertigo has been more or less constantly in use. I 

 do not think that Dr. Dall can brush aside these facts by stigmatiz- 

 ing the distinction for which the name has always stood as " practi- 

 cally valueless," and proceed to fasten a totally new significance 

 upon it. Quite a respectable company of conchologists of high rank, 

 including Pfeiffer (in the Nomenclator Hel. Viv.), find use for Alsea 

 in the sense established by Gray, as set forth in my former note. 



I do not wish to be understood to break a lance insupportof the value 

 of ^/«a as a division of Vertigo ; butadivision adopted byPfeiflTer and 

 other high authorities is at least entitled to respectful consideration. 

 It seems inadvisable to use the name of such division for a totally 

 different group, at all events until malacologists recognize a Supreme 

 Authority who shall pronounce once for all upon what distinctions 

 are "practically valueless," — a consummation remote from this con- 

 tentious generation. 



The facts are, in short, as follows : (1) Jeffreys regarded the 

 toothed forms of his list as typical of his group. Gray in 1847 

 selected one of these, P. antivertigo, as type, that species never be- 



