Occasional Papers of the Museum of Zoology 9 



The description of P. acuta, though short, does not apply 

 to any other Pleurocerid belonging to the I^ake Erie fauna, but 

 does, as it seems to me, imniistakably cover the species so well 

 known as subulare Lea. 



That acuta Raf. and subiilaris Lea are the same species is 

 shown conclusively by the following comparison of the orig- 

 inal descriptions, in which every word of both, and nothing 

 else, is included. 



Plcuroccra acuta Kaf. Mclania siihularis Lea. 



Elongate, very acute. Elevated and acutely turreted, 



apex acute, horn color. 



Flat, nine spires, the fi'-st an- Whorls about twelve, flat, car- 



gular in front. inate on the middle of the 



body-whorl, base angulated. 

 Aperture white and one- 

 fourth the length of the sliell. 

 Length i .3 ; diam. .4 in. 



Lake Erie. Niagara River 



Dr. Lea could almost be convicted of plagiarism on tliis 

 showing. If this identification is correct, then under the ruling 

 of Opinion No. 46, Plciirocera acuta Raf., being the first iden- 

 tifiable species described as Pleurocera and complying with the 

 original generic diagnosis, automatically becomes the genotype 

 as being the "only species available as a type."' 



IV. 



While I think that under the showing made, it is unneces- 

 sary, nevertheless, to put the question beyond any peradven- 

 ture of a doubt, I hereby identify Pleurocera acuta Raf. as 

 the species subsequently described by Lea as Melania suhularis 

 and do further designate it as the type of the genus Pleu- 

 rocera Raf. 



