THE NAUTILUS. 57 



1876, Tapparone-Canefri, C. Genere Melibe Rang; MeUbe- t 

 papillosa De Filippi. Memorie della Reale Accademia 

 delle Scienze di Torino. Ser. 2, T. 28, pp. 219-220. 



1883, Tryon, Jr., George W. Structural and systematic con- 

 chology. Mollusca, 2. 



ON THE GENEEIC POSITION OF ANCYLUS FLTJVIATILIS MULLER 



BY BRYANT WALKER 



IN discussing the availability of Ancylastrum Bgt. as a 

 generic receptacle for Ancylus fluviatilis Mitll., in case Ancy- 

 lus could not be used, (ante, p. 5) I stated that the position 

 of Kennard and Woodward in claiming that Potella lacus- 

 tris L. was the correct type of Ancylus was "by no means 

 free from doubt ". A subsequent and exhaustive considera- 

 tion of the argument advanced by them in support of their 

 proposition convinced me that from the data then known 

 their position was untenable. But Mr. Kennard has recently 

 unearthed an ancient paper, apparently entirely overlooked 

 by the bibliographers, which puts an entirely different com- 

 plexion on the question. 



It appears that in 1823-4 there was published anonymously 

 iil Vol. XV of ' ' The Quarterly Journal of Science, Literature 

 and the Arts " of the Royal Institution of Great Britain a 

 series of articles 011 " Lamarck's Genera of Shells ". In, 

 1823 these articles were reprinted from the original type, 

 with only a change of pagination, bound together and 

 published with a new title page and a portrait of Lamarck. 

 This title-page reads as follows: 



" Lamarck's / Genera of Shells / Translated from the 

 French / By J. G. Children F. R. S. / with plates / from 

 original drawings / by Miss Anna Children / 1823." 



In this paper (p. 231 of the original, p. 94 of the re- 

 print) there is given a sufficient generic diagnosis of Ancylus 

 followed by this statement : 



" Type. Ancylus lacustris (Patella lacustrisi Linn.)." 



A very fair figure of the type species, which is the species 

 commonly called lacustris, is given on pi. VII, fig. 121. 



