1909.] 



NATURAL SCIENCES OP PHILADELPHIA. 



545 



Fig. 4. S. supracostata. 



spire conic, very obtuse at the summit; thin, corneous. First 2^ 



whorls are smooth and convex; then regular, distinct fold-like striae 



appear below the suture. These striae are a little protractive and do 



not extend quite to the suture below. On the 



last whorl there are 3 or 4 striae in the space of 



a millimeter; they weaken downwards, and fade 



out below the middle of the whorl. Whorls 5^ to 



5f, convex, the last slightly compressed laterally, 



convex below. The aperture is small, outer lip 



arching forward in the middle; columellar fold is 



very strong and short. 



Length 10, cliam. 4.9, aperture 5 mm. 

 9.6, " 4.8, " 5 " 



State of San Luis Potosi, at the cave near San 

 Dieguito; types No. 99,031 A. N. S. P. Also at 

 El Abra and the canyon below Las Canoas. 



This is quite distinct by its comparatively 

 long but very obtuse spire, regular sculpture 

 and very strong columellar fold. It is somewhat 

 related to S. physodes Shuttl. 



Streptostyla bartsrhi Dall, one of the finest species of the genus, was 

 taken in the canyon below Los Canoas. 



Streptostyla minuta n. sp. Fig. 5. 



The shell is oblong-conic, amber colored, somewhat transparent; 



spire long, with slightly convex outlines and very obtuse summit. 

 Surface smooth and glossy. Whorls h\, slightly con- 

 vex, parted by a well-impressed suture, narrowly 

 margined by transparence. The aperture is about 

 half the total length of the shell, narrow; outer 

 margin of the peristome arched forward in the 

 middle. Columella short, very strongly twisted, the 

 fold having a heavily calloused rounded edge. The 

 edge below the spiral fold is deeply concave and 

 thin. Length 5.5, diam. 2.3, length of aperture 2.6 mm. 

 Mountain sides of the canyon below Los Canoas, 

 State of San Luis Potosi. Type No. 98,595 A. N. S. P. 

 This is by far the smallest species of the genus 

 known. It is chiefly remarkable for the small aper- 

 ture, long spire and the very strong columellar fold. 



In size and general appearance it resembles Coehlicopa lubrica. Two 



specimens were taken. 



Fig. 5. S. minuta. 



