196 



BULLETIN OF THE 



outer lip. Aperture shaped as in muscorum, having a single small parietal denticle. 

 Altitude 3f, diameter If mm. 



Pupa syngenes, Pilsbrt, The Nautilus, 1890, Vol. IIL p. 296, Plate V. Figs. 1, 2. 



Two specimens of this form are before me, and I am in doubt whether to give 

 them a new name, as they may be only sinistral monstrosities of the common 

 P. muscorum. The shells are labelled "Arizona" in the Academy collection, col- 

 lector not known. 



(Since the above paragraphs were in type, I have received a communication from 

 my friend, Dr. V. Sterki, to whom I sent a specimen of P. syngenes, which I at first 

 described as a variety of muscorum. He says : — 



" I am satisfied that it is a species, and not a var. of muscorum ; the shape of the 

 whole siiell, the last whorl so considerably flattened, and ascending, the number of 

 whorls, seem to me to prove its specifical rank. . . . After washing out the aper- 

 ture of your specimen, I saw a rather strong lamella or tooth on the columella, and 

 a barely perceptible trace of an inter-palatal lamella, which, however, is validified 

 by the impression on the outside.") 



The above is Pilsbry's description. 

 Sterki is figured here. 



An authentic specimen drawn by Dr. 



Vertigo ovata, Say. 



Of F. tridentata Sterki writes (The Nautibis, 1890, p. 135): "It has a 

 wide distribution in the northern part of the country ; originally found in 

 Illinois, it has been collected in different parts of Ohio and New York, as 

 well as in Minnesota and Colorado. In general it is remarkably constant in 

 its characters ; yet there are slight differences ; here I found a few examples 

 from low ground, together with V. ovata; they were a trifle larger, with a 

 thicker and deeper colored shell than those from upland places." 



