30 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
have graded floors some distance inward from their mouths; the 
ridges are for the most part rounded off at their ends, and descend to 
the piedmont plain without the least indication of terminal facets; and 
no recent fault scarps were seen across the flat piedmont fans. Hence 
if the range is a faulted block, it is in a much more advanced stage of 
dissection than the Wasatch range, as has already been inferred from 
the openness of the Sevier canyon. Before pronouncing definitely on 
this point, more study of the base line is desirable. There is, however, 
yet to be described a curious feature which supports the supposition 
of block faulting. 
About midway between Lemington and Oak City there is a huge, 
maturely dissected landslide at the western base of the range. We saw 
Fie. 10.— Looking north along the western side of the Canyon range, from the 
in the middle distance. 
it in the distance as we came up from the Sevier strath, when it seemed 
to be an outstretching spur, extending two or three miles from the body 
of the range; as such it was distinctly unlike the expectable features 
of a dissected block mountain. ‘The road turns westward around the 
slide, and as we were told afterwards follows a Bonneville shore line 
that has been cut on its end, where many large boulders are exposed. 
We left the road and crossed over the slide near the range. It was 
composed of a most heterogeneous mixture of red and white quartzite, 
pebbly quartzite, and limestones, in fragments of all sizes up to six 
feet or more. Not a single ledge or outcrop was seen, although out- 
crops of quartzite strata, which dipped gently into the range, were 
abundant on the mountain flanks. Moreover the landslide was 
deeply and maturely dissected by branching valleys with graded side 
slopes; there was not a trace of the hill-and-hollow forms such as 
young landslides commonly possess. Many of the boulders had 
weathered and flaked to somewhat rounded forms. Hence the date 
