1905.] NATURAL SCIENCES OF PHILADELPHIA. 249 



Ashmunella esuritor n. sp. PI. XIII, figs. 2S-26. 



The shell is rather solid, light brown, biconvex, angular at the periph- 

 ery. The cylindric umbilicus is suddenly dilated in the last whorl. 

 The surface is irregularly marked with slight growth-wrinkles, and on 

 the last whorl there are impressed spiral lines, more or less irregularly 

 developed and sometimes almost obsolete. Some intermediate whorls 

 are indistinctly punctulate. Spire low-conic. Whorls 6^ to 6^, 

 slowly increasing. The first three whorls are convex, the rest more or 

 less flattened. The last whorl is distinctly but not acutely angular in 

 front, but becomes rounded in its later half. The suture descends a 

 little to the aperture, and the whorl is rather deeply guttered behind 

 the lip. The aperture is very oblique, roundly lunate. The peristome 

 is white, thickened within, and equably reflexed. In the middle of the 

 hasal margin there is a low, indistinct prominence, but there are no other 

 traces of teeth. The parietal callous is thin except in old specimens, 

 when it is thickened at the edge, forming a cord across the whorl, 

 Alt. 7.7, diam. 15.5 mm. 



" 7.7, " 15 " 



" 7.5, " 15 " 



" 7, " 14.5 " 



Chiricahua Mountains, in Bar (or Bearfoot) Park. Types No. 

 87,023, A. N. S. P., collected by James H. Ferriss, February, 1904. 



At first glance this form seems to be a small angular race of A. chiri- 

 cahvxina; but upon closer study it seems far more likely that it is a 

 terminal member of the A. angulata group, in which the teeth have 

 degenerated. The slight flattening of the whorls, the shape of the 

 mouth, and a faint punctation observable near the end of the third 

 whorl in the freshest specimens, all indicate this relationship. Most 

 of the fully adult and old individuals seen have lost much or all of the 

 cuticle, and are dull flesh-tinted. 



The spiral engraved lines vary a good deal in different specimens, 

 and when slightly corroded neither spirals nor granulation are visible, 

 even in living shells. 



The smaller size, angular periphery and comparatively wider lip 

 readily distinguish A. esuritor from A. chiricakuana. 



The genital system (PI. XXI, figs. 30, 25) resembles that of A. chiri- 

 cahuana except that the ducts are very much shorter, both absolutely 

 and in comparison with the size of the shell ; and the spermatheca and 

 its duct are nearh'- as long as the penis, epiphallus and flagellum. The 

 extruded penis and atrium in another specimen are shown in fig. 25. 



