1916.] NATURAL SCIENCES OF PHILADELPHIA. 331 



connection with a study of our own material, both in the field and 

 in the laboratory, convinces us that the forms mentioned in the 

 foregoing synonymy should not be separated as subspecies. Some 

 of the names may be useful as descriptive terms, provided they are 

 used in such a way as to indicate their rank. The form albofasciata, 

 especially, is a good color form, but the same variation is seen in 

 various colonies of depressa and cooperi, though seldom or never 

 quite so strikingly developed. 



Hemphill says of castaneus that most of them are "faintly marked 

 with the broad white band of albofasciata, but a few are plain chestnut 

 colored." This is exactly the variation that occurs sporadically in 

 many colonies of depressa and cooperi, and did not warrant the 

 sending out of material from that colony under a distinct name, 

 though it may have been appropriate to have selected the plain 

 chestnut-colored examples and sent them out as mere color forms. 

 Four specimens in Clapp's Hemphill collection are labelled castaneus^ 

 Two of them, from Box Elder County, Utah, are almost typical 

 albofasciata. The other two, from Eastern Oregon, are not at all 

 closely related to the others, and appear to be simply dark, unbanded 

 examples of some undetermined species such as so frequently occur 

 sporadically. The separation of the forms midticostata and gouldi 

 was based chiefly upon a slight difference in the number and promi- 

 nence of the ribs. As the ribs are extremely variable at all the 

 stations of the species, and the material separated and labelled by 

 Hemphill shows minute gradation in this respect, as well as in color 

 and form, throughout his whole group of "varieties" from this 

 district, probably no good purpose is served by retaining both of 

 the names, though the average of the ribbing is so much more pro- 

 nounced at some localities that it may be convenient to retain one 

 of the names without giving it subspecific rank, in which case 

 midticostata should be selected. 



St a. 29, steep east bank of Bear River below Cache Junction, 

 just above the entrance to the gorge by which the river breaks 

 through the mountain range to Wheelon, under shrubbery on whitish 

 limestone. Oreohelix, connecting the unbanded forms of peripherica 

 with the strongly banded albofasciata form. In examining 69 live 

 specimens from a space about two rods wide and several rods long, 

 30 (form binneyi) are found to have scarcely a suggestion of color 

 bands; 26 (form albofasciata) have a dark band 3 to 4 mm. wide 

 just below the suture, then a white peripheral band of about the 

 same width, a dark band below the periphery varying from 1 to 

 23 



