232 AMERICAN JOURNAL 



the "interior of Oregon," and as I have been over nearly their 

 whole route, 1 think the locality must have been "Lapwai," 

 Montana, along the Koos-koosky River, near lat. 46°, the farthest 

 inland they reached. Mr. Hemphill found it near the same 

 locality (Newcomb), but the aolitaria was not found there. Mr. 

 Bland found among my specimens of Oooperi, a "colorless 

 worn specimen, with umbilicus more like that of strigosa, and 

 which may be an elevated form of that species or a variety of 

 Oooperi." Thus the two are connected by intermediate speci- 

 mens, possibly hybrids, like Mormonum and 1 1 illibrandi or Co- 

 lumbiana and germana. It is noteworthy that strigosa descends 

 the lowest to the border of the forest region, about 16U0 feet 

 elevation, in lat. 40°, solitaria occurred only above 2500 ft. 

 in lat. 47°, and Cooperi (of Bland), only at f)500 ft. on the east- 

 ern (and driest) slope of the Rocky Mountains. It will be in- 

 teresting to compare the altitude at which they were found in 

 Arizona, if possible. The " Great Plain of the Columbia," for 

 200 miles wide in hit. 47°, is so dry as to furnish no Ilelicoids, 

 and there are still drier and more extensive desert plains in 

 Nevada, Utah, and Arizona. " Between Idaho City and the 

 Cceur d'Alene mining district," is the rather indefinite locality 

 given by Mr. Hemphill for Anguispira Idahoemis, Newc, the 

 same as be gave for .1. strigosa. As no one else has found it 

 north or east of Snake River it was probably from the western 

 slopes of the Rocky Mountains, south of lat. 40°. Such an 

 unique species, like a- magnified PseudoJiyalina exigua, (Stp.), 

 recalls the similar relation of II. ? potygyrella to llclicodiscus 

 Uneata, (Say), and makes the examination of the animal's soft 

 parts exceedingly desirable. 



From this point of the Rocky Mountains I believe no Ileli- 

 coids have yet been found, except A. Cooper/, which occurs in 

 lat. 41°, and New Mexico. A. strigosa also occurs with it, and 

 reappears near hit. 33° in Arizona, as before mentioned. A 

 Careful search will probably discover others also. 



The CoBur d'Alene Mountains, near lat. 47°, 'seems also to be 

 the peculiar habitat of TriodopsiB Mttllnni, Bid. It was most 

 common on their west slope, down to about 1500 ft. elevation, 

 but I found one more delicate and depressed specimen on the 

 east side of the range, 30 miles below the junction of the Bitter- 

 root River and llell-gate River, at an elevation of 4000 ft., and 

 others between them. .St. Joseph's river runs into Cceur d'Alene 

 Lake on the north, near lat. 47°, and is now in Idaho, formerly 

 part of Oregon." This is the most southern point yet recorded 

 for the species, and the range is so far limited to 110 miles east 

 and west, and 40 north and south, but the species has probably 



