The Nautilus. 



Vol. III. DECEMBEE, 1889. No. 8 



DESCRIPTION OF A NEW AMERICAN HELIX. 



BY F. A. SAMPSON. 



Ou the Bo.stou Mountain.s, Crawford Co., Arkansas, I found some 

 shells which niay he descril)ed as follows : 



Triodopsis edentata, n. .«p. 



Shell inij)erforate, depressed, with granulate striations, thickly 

 covered with hair-like projections ; whorls 5, the la.st strongly con- 

 tracted at the aperture ; suture not much impressed ; spire short, 

 obtuse ; parietal wall with a long arcuated white tooth ; 

 umbilical region imi)ressed ; aperture contracted by a 

 deep indentation behind the peristome; on the inner 

 margin of the peristome are two enlai'gements or obsolete 

 teeth, one near the base, the other midway between it 

 and the right terminus of the peristome. 

 Greater diameter ISs, lesser 12, height 7 mill. 

 T. injieda in Arkansas varies from 9 to 12 mill, diameter, and the 

 larger shells in general appearance are very much like this species 

 with the exception of the teeth on the peristome. Had I found but 

 one or two specimens I would have taken them to be immature 

 inflecta of large size, but I found a dozen living and dead shells the 

 latter part of February, and they were all destitute of peristome 

 teeth, and are as much entitled to specific distinction as Triodopsis 

 Rugeli Schutt, in which the difference from inflecta is the distance 

 of the upper tooth of the peristome within the aperture. 



In this species the enlargements of the peristome correspond in 

 position with the teeth of inflecta, but it is hardly proper to call 



