TJ1K NAUTILUS. 123 



collected by him on Bright Angel Trail, at Grand Canyon, Arizona, 

 in 1913. He was collecting fungi, and unfortunately did not note the 

 exact locality of the snail find, but writes that he followed the trail 

 closely, and thinks he got the shells " about one hundred yards wect 

 of the upper limit of the trail and not more than twenty feet below 

 'lie top," though he cannot be certain and '' may have gotten them 

 as far down as the half way house. " He supposed them to be com- 

 mon and made no note of the place. They are much larger than the 

 common S. coloradoemis of that region, and differ in other respects- 

 They did not seem to fit the description of any other species, but the 

 finding of so large a species along a trail which has been searched by 

 some of our ablest conchologists and most thorough collectors made 

 me doubt that it could be new, so I sent two specimens to Dr. Pilsbry, 

 who pronounced them undescribed. 



SONORELLA BETHELI, new Species. 



Shell rather large, moderately elevated. Whorls five and one-half 

 convex, increasing regularly in size, the last descending about one 

 millimeter in the last five millimeters to the aperture. Lip slightly 

 everted, more strongly so at the base of the aperture, and somewhat 

 reflected over the umbilicus, its terminations connected by a thin 

 transparent callus. Umbilicus moderate, open to the apex. Aper- 

 ture shortly oval-lunate, oblique. Growth-lines fine, but well-defined 

 under a lens ; numerous wrinkles, usually rounded, occasionally acute, 

 coincident with the growth-lines but of course much less numerous. 

 The most interesting character of the species is the spiral sculpture, 

 unusual in this genus, consisting of numerous incised lines, slightly 

 flexnous over the tranverse wrinkles, covering the last whorl from 

 umbilicus to suture, and extending without diminution over the an- 

 terior half of the penultimate whorl, above which they begin to dis- 

 appear. Though the four specimens at hand are all more or less 

 weathered, one shows the periostracum to be smooth and shiny, and 

 probably originally of Isabella color. One dark-brown spiral band, 

 reaching a width of about one millimeter on the last whorl, occurs 

 just above the periphery, so as to be concealed on all but the last 

 whorl and the anterior half of the penultimate. 



Measurements in millimeters : Type (in Univ. Colo. Museum), 

 maj. lat. 21, min. lat. 18.5, alt. 14, alt. measured just in frontof 

 aperture 10.5, height of aperture 9.5, width of aperture to callus 



