36 BULLETIN OF THE 



Polygyrella polygyrella, Bland. 



Plate I. Figs. 6, 7 ; Plate VI. Fig. 8. 



Also in Deer Lodge Valley, Montana (Hemphill). 



The genital system (PI. III. Fig. 8), as would be anticipated, is characterized 

 by the length of all the organs. The penis sac (p. s.) is long, narrow, cylin- 

 drical, receiving the vas deferens at its blunt apex, and bearing the retractor 

 muscle just below. The genital bladder (g. b.) is long, narrow, pointed above 

 and below ; its duct is long and narrow. The testicle and ovary are long and 

 narrow. 



Triodopsis Levettei, Bland. 



Plate I. Fig. 16. 



See Supplement to Vol. V. p. 154. 



Also seventy miles southeast of Tucson, in the Huachuca Mountains, Arizona. 

 A species of the Central Province rather than of the Texas Region, as suggested 

 in " Manual of American Land Shells." 



Triodopsis Mullani, Bland 



I am convinced by larger suites of specimens that I was wrong in referring 

 (Vol. V. p. 333) this species to Mesodon devius. The group is very puzzling, 

 and some confusion has resulted from my treatment of it. It must, therefore, 

 be considered that Triodopsis Mullani, Bland, as described and figured by him 

 is a distinct species confined to the regions east of the Cascades in Northern 

 Idaho. It is very globose, with a decidedly tridentate aperture. (See Vol. V. 

 p. 338, Fig. 222, and Man. Amer. Land Shells, p. 119, Fig. 87, for a copy of 

 Bland's original description.) Tlie shell I describe below as T. Sanhiirni is 

 somewhat nearly related to Mullani, but has its aperture much more contracted 

 by the teeth on the peristome and the more developed parietal tooth. T. Har- 

 fordiana is the form which in Terr. Moll., V. (309, Fig. 203) I mistook for Poly- 

 gyra Harfordiana (see Suppl. p. 151). It is a small shining shell, flattened, 

 with larger umbilicus and less developed teeth. Triodopsis Hemphilli is a 

 nuich larger, coarser, russet-colored shell, scarcely umbilicated, with a small 

 parietal tooth, and a slight approach only to the lamellar dilatation of the inner 

 edge of the peristome so characteristic of the typical devius; no denticle on the 

 outer edge of the peristome. All these forms show the scars on the epidermis, 

 though no hairs were present in my fresh specimens. Besides these well-marked 

 forms are found individuals, not associating with them, which seem to connect 

 Harfordiana with Mullani (see Terr. Moll., V. Fig. 221, and the following, PI. I. 

 Figs. 6, V). The typical Mesodon devius is confined to the Pacific Province. 

 See Terr. Moll, IV. PI. LXXIX. Fig. 13 ; V. Fig. 220. It is a very di^^tinct 

 species, as yet not noticed in the Central Province. 



