OF CONCHOLOGY. 238 



been found farther north. It is interesting as being hirsute, a 

 rare character in this genus, but is not subangled, and inhabits 

 quite a moist climate. 



Review op the Larger Species. 



Looking now at the distinction of the species in connection 

 with their affinities, the following striking facts are presented to 

 us as to the large ones. 



In the Rocky Mountains, about lat. 4G° to 47°, we find a 

 group of large lipless species, somewhat intermediate between the 

 HelUeellince and Hellicidce, which have been considered nearest 

 allied to the type of Anguispira, Morse, [alter nata). These are 

 A. Cooperi (perhaps also solitaria) and strigosa, the latter a sort 

 of sub-species of the former. The large Mac. Vancouveremfa 

 skirts the western base, and several minute species occur. A. 

 ? Idahoensis can scarcely be culled lipless, as every rib forms a 

 lip as it grows. If. f polygyrella has a thickening of the peri- 

 stome and a parietal tooth, like the Polygyrce^ which, however, 

 do not approach within 1000 miles of its habitat, and are con- 

 fined to subtropical climates. H. ? Townsendiana forms a con* 

 necting link between the unseulptured eastern albolabris group 

 and the sculptured and banded Californian species, having been 

 associated with both by systematizers. It stands alone in many 

 points, though future comparisons may discover that more thanone 

 species is called Townsendiana, and that anachoreta is allied to 

 it. Triodopsis Midlani stands as the sole representative of several 

 eastern species, and even this varies in being hirsute as well as 

 marked with fine revolving impressed strise, a character rare in 

 eastern Helicoids but common in western, and distinguishing A. 

 Cooperi from solitaria. 



The Anguispira form the peculiar Rocky Mountain group, in- 

 habiting a region of nearly uniform rain-fall, extreme cold* in 

 winter and great heat in summer. Wherever they arc found 

 limestone has also been discovered, chiefly carboniferous. 



Passing round the northern limits of the Columbia Plain, near 

 lat. 49°, we find only two of the species following us to the 

 coast, and one of these is known to be far northern, while the other 

 probably extends much farther north. We also meet with Co- 

 lumbiana, allied in form to the eastern monodon with an ap- 

 proach to that of the albolabris group. This has also a toothed 

 and often subcarinate ally apparently small and rare in Oregon, 

 but finer and more rounded southward ; a development of a 

 warmer climate, the subcarinate forms probably on high mountains. 

 Another, 0. devia, is much more closely connected with the albo- 



