34 THE NAUTILUS. 



Two largest Height 8, diam. 19 mm. 



Height 8J, diam. 16.5 mm. 



Two smallest Height 7, diam. 16.4 mm. 



Height 8, diam. 15.6 mm. 



ASHMUNELLA DANIELSI 11. Sp. PI. 2, figs. 1. 



The shell is similar to A. tetrodon in shape, luster and color ; 

 but it differs in the following characters. The fine spiral lines, 

 when the surface is perfectly preserved, are numerous and dis- 

 tinct. There is never any trace of a parietal tooth. The two teeth 

 of the basal margin are closer together, and the inner one is 

 much smaller than the outer, the umbilicus is a trifle smaller. 

 Finally, the callous rim strengthening the lip of the young, in 

 resting stages, is not absorbed, but remains visible as an internal 

 varix, producing an opaque streak in the adult, visible extern- 

 ally on the base, or if the surface is dulled, it may be seen by 

 holding the shell up to the light. 



Height 7, diam. 14.5 mm. ; 5J whorls. 



Height 7, diam. 13.3 mm. ; 5 whorls. 



Locality. Cave Spring Canyon (near the south fork of White- 

 water Creek, Range 19 West on the parallel of 33 20', U. S. 

 G. S. Topographic Map, Mogollon Quadangle). Socorro Co., 

 New Mexico. 



This species is remarkable for retaining large lip-teeth while 

 the parietal tooth has totally disappeared, showing that these 

 teeth are not connected in inheritance, though from the diminu- 

 tion of all together in A. t. mutator a connection would be 

 supposed to exist. The large series taken at stations 57, 58, 

 59 show very little variation. As in A. tetrodon, the basal 

 teeth are yoked together, by a callus resembling the letter U. 



About seventy of these were collected in the lower station (56) 

 of Cave Spring Canyon, a large number broken by the mice. 

 Elevation about 7,000 feet. This canyon is about two miles 

 north, running parallel with the Little Whitewater. No other 

 large shells were found there. 



Station 57. About two miles farther up the canyon on large 

 slides, one-half mile below Kitt's new mine and cabin, were 

 Ashmunellas in unlimited numbers, in company with Oreohelix 



