16 Remarks on Certain Species of 



form, labrum reflected, regularly arcuated, describing two-thirds of a 

 circle ; within two-toothed, teeth not separated by a remarkable sinus ; 

 labrum with a profound duplicature, which terminates in an acute angle 

 at the centre of the aperture ; beneath exhibiting only two volutions, 

 of which the external one is slightly grooved near the suture. 



" Inhabits Alabama. Breadth one-fourth of an inch. Cabinet of the 

 Academy. 



" This species is about the same size as P. avara* but, besides other 

 characters, it is sufficiently distinguished by the acute fold of the 

 labrum. It was sent to the Academy by Mr. Samuel Hazard." 



No author appears to have correctly identified this species. 

 If distinct, as I fully believe it to be, the name must be 

 changed, inasmuch as IT. plicaia Born is of prior date. Mr. 

 W. G. Binney informs me that in Say's MS. there is an erased 

 remark as to the name being pre-occupied, and proposing hefa. 

 As Pfeiffer has already trespassed on the Greek alphabet, I 

 would suggest the propriety of dedicating the species to its 

 discoverer, Mr. Hazard. 



This shell may be distinguished from fatigiata Say, and 

 Troostiana Lea, independently of the absence of the carina, 

 by its smaller size, and more particularly by the different 

 form, relative size, and position of the teeth. In those .species 

 the superior tooth on the peristome is transverse, comj)ressed, 

 and larger than the inferior one, from which it is separated by 

 a " remarkable sinus," distinctly visible on looking into the 

 aperture ; the inferior tooth is obtuse. Immediately behind 

 the peristome, the position of the teeth is marked by small 



* Say describes P. avara as having 4 whorls, covered with numerous short 

 robust hairs, and with no groove on tlie last whorl. He gives a quarter of an 

 inch as the breadth. This is very diflferent to the shells generally bearing the 

 name of avara. I have one specimen in my cabinet, given to me by Dr. Budd, 

 which agrees closely with Say's description. 



