TROCHOMORPHA. 119 



Form hemphilli Newc. is a variety existing over a considerable 

 territory in Nevada, Idaho, Utah and Colorado. It is depressed, 

 carinated, and begirt with fine thread-like spirals. Form gabbiana 

 Hemph. (pi. 42, figs. 12, 13) is "a coarse, rough haydeni with the 

 revolving ribs nearly or quite obsolete." It passes into strigosa. 

 Form bruneri Ancey (or oquirrhensis Hemph.) has the spirals more 

 developed than in hemphilli, but less than in haydeni. The ends of 

 the peristome approach and are joined by a heavy callus. Form 

 haydeni typical (vol. Ill, pi. 10, figs. 40, 41) is the most divergent 

 of all, having very strong spiral cords and decussated intervals. 



Another form, quite intermediate between oquirrhensis and strigosa, 

 has been called var. hybrida by Hemphill. It is from near Logan, 

 Utah. 



Genus TROCHOMORPHA Alb. (Vol. Ill, p. 72.) 



The following species were not included in Tryon's account of this 

 group in vol. III. 



T. HAENSELI Schmacker and Boettger. PI. 30, figs. 6, 7, 8. 



Shell moderately widely umbilicated, the umbilicus } the diam. 

 of the shell ; conic-depressed, compressedly carinated, shining, olive- 

 brown, unicolored ; spire little raised, exactly conical, apex rather 

 acute. Whorls 6j, very slowly increasing, very slightly convex, at 

 the suture distinctly hair-marginate, costulate-striate, without spiral 

 lines ; the last whorl rather convex beneath, roundly angled around 

 the umbilicus, scarcely wider than the penultimate whorl, hardly 

 descending. Aperture moderately oblique, irregularly -rhomboidal ; 

 peristome simple, rather obtuse, the upper margin very short, sigmoid, 

 little protracted, basal margin receding in the middle, columella 

 obliquely ascending, almost subangulated where it joins the basal 

 lip, both subcalloused and slightly reflexed. 



Alt. 5-51, greater diam. 122-132 mill.; apert., alt. 3i-3!, width 

 41-5 mill. (8. & B.) 



South Cape of Formosa. 



T. haenseli S. & B., Nachr.-Bl. 1891, p. 152, t. 1, f. 5. 



T. borealis Mlldff. (Nachr.-Bl. 1888, p. 39) is closely allied, but 

 smaller, less dark, the umbilicus narrower, the spire rather convex- 

 conic, and the keel less acute ; the basal lip is also more deeply 

 S-shaped in the continental species. 



