186 



BULLETIN OF THE 



This is a very dark, intermediate form of Jidelis, which in its southern march 

 under changed conditions assumes a more carinated form, and is known to con- 

 chologists as infumata, Gould. 



The above is Mr. Hemphill's description. 



Arionta Coloradoensis, Steaens. 



Shell orbicular, moderately depressed, whorls slightly elevated, apex obtuse, 

 number of whorls four to four and a half, rounded. Umbilicus narrow, showing the 

 penultimate whorl, though partially covered by the reflection of the lip at the point 

 of junction with the base of the shell. Aperture obliquely ovate, nearly circular, 

 and almost as broad as high. Lip slightly thickened and reflected, or simple, vary- 

 ing in this respect; more reflected and aperture more eff"use at the columella. 



Parietal wall in the heavier examples calloused, the callus connecting with the 

 inner edges of the outer lip above and below. Shell rather fragile, thin, translu- 

 cent ; surface smooth and shiny, and sculptured with fine incremental lines. Color 

 pale horn to white, and otherwise marked by a single narrow revolving reddish 

 brown band just above the periphery, which in some specimens is obscure or 

 absent. In some individuals certain faint scars upon the upper whorls imply an 

 occasionally hirsute character. 



mm. 



Maximum diameter of largest 15.25 



Minimum diameter of largest 13.25 



Altitude of largest 10.25 



Maximum diameter of smallest adult 13.75 



Minimum diameter of smallest adult 12.00 



Altitude of smallest adult 8.75 



Grand Canon of the Colorado, opposite the Kaibab plateau, at an elevation of 

 3,500 feet. (Mus. No. 104,100.) 



The above, while exhibiting a facies or aspect of its own, its nevertheless sug- 

 gestive of i7. Remondi, Gabb, Mazatlan, in the Mexican State of Sinaloa, and also 

 from the high mesas or table lands in the neighborhood of Mulege, Lower Cali- 

 fornia. H. Carpenteri, Newcomb, which is a synonym of H. Remondi, is credited 

 by the author to " Tulare Valley," and has been found in other localities in Cali- 



