MUSi!-UM OF COMPAKATIVE ZOOLOGY. 29 



A. SHELL TRANSVERSELY RIBBED. 

 Var. Idaho ensis, Newcomb. 



Plate II. Fig. 13. 



In the comparison of the various forms here given, I call this a variety. I 

 am, however, convinced of its specific weight. 



The transverse ribs in this are few, separated, and stout. There are twenty- 

 four upon the body whorl of one individual. It has as yet been found only in 

 Idaho. I give a new figure of a Salmon River Mountain specimen. 



Var. Binneyi, Hemphill. 

 Plate II. Fig. 13. 



Box Elder County, Utah (H. Hemphill). (See p. 31.) 



This variety has strong rough wrinkles rather than decided ribs, about fifty 

 on the fir>?t whorl of one individual. Some individuals have a decided, erect 

 tubercle within the peristome near its junction with the parietal wall of the 

 aperture. There are no revolving bands of color. 



This is the first of a remarkable series of varieties or species lound by Mr. 

 Henry Hemphill in the region of Great Salt Lake, Utah. I will here give his 

 own description of the habitat of these forms : — 



" I commenced collecting at or near Ogden, Utah, and almost the first shell 

 1 picked up was the variety I call JVasatchensis. (See p. 34.) This pretty 

 and interesting shell I found living among quartzite boulders, in crevices sufti- 

 cientl}'' large to aff"ord cool and moist retreats during the active summer season, 

 and safe places for hibernating during the cold winter months. This shell 

 seems to be confined in its range to a very limited area, for I did not find a 

 single specimen either dead or living outside of a little plat containing an acre 

 of ground. I have often admired this shell, and think it one of the most inter- 

 esting varieties I found in Utah, as it combines the characters of Idahoensis, 

 Haydeni, and Hemphilli, as well as of Gooperi. Not only on this account is it 

 interesting, but because it is found living on or near the dividing line between 

 the Idahoensis group and the Haydeni group.* North of Ogden you will see I 

 found all the transverse-ribbed varieties, and south of Ogden all the longitu- 

 dinal ribbed varieties were found, with the exception of the variety of strigosa, 

 just assuming the Haydeni sculpturing (near Logan). Not a single transverse- 

 ribbed specimen occurred south of Ogden. AVhether this is merely accidental, 

 or whether there are some local causes on either side of this line which influ- 

 ence this change in sculpturing, I cannot say. I only point to the fact, and 

 that it seems a little strange that Wasatchensis should be found just on this 

 line. 



" In the gulches near Ogden, and also on the mountain slopes among rocks 

 and leaves, I found the typical strigosa and Coo-peri, as well as a number of 

 small shells. 



* That is, the transversely ribbed and longitudinally ribbed groups. 



