68 HOuOSPIRA. 



16 ; Crosse, 1892, 16 species ; Dall, 1895, 22 species ; von Mar- 

 tens, 1897, has 12 species (those from the United States being 

 omitted) . The present work describes 28 species. 



Most of the forms are known from the type localities only ; 

 and while the range of many of them will doubtless be ex- 

 tended by further collections, it is obvious that they are much 

 more restricted in habitat than most of the land snails of other 

 families inhabiting the same regions. Though usually occur- 

 ring in abundance where found, they seem to be exceedingly 

 local. 



The only fossil species referable to this genus is the Puerco 

 (lower Eocene) Holospira leidyi (Pupa leidyi MEEK, Sixth 

 Ann. Rep. U. S. Geol. Surv. of the Terr, for 1872, p. 517 ; 1873. 

 WHITE, Bull. U. S. Geol. Survey no. 34, p. 27, pi. 5, f . 8, 9, 10 ; 

 1886), from near the town of Nacimiento, New Mexico, and 

 also from the base of the Bridger or top of the Green River 

 Group, 12 miles south of Fort Bridger, Wyoming. While not 

 absolutely conclusive, this species seems to have all the fea- 

 tures of Holospira, as Meek himself suspected. In New Mex- 

 ico it occurs with Helix nacimientensis White, a form appa- 

 rently referable to the Mexican genus Lysinoe, judging by the 

 size, the circumumbilical angle, etc. 



Soft Anatomy of Holospira. 



The foot is small, narrow for its length, and in H. roemeri, 

 dalli, strebeliana and nelsoni the sole is undivided. In several 

 dried specimens of H. goldfussi Strebel discerned a very nar- 

 row median band. The tail is depressed ; upper surface gran- 

 ulose, with a prominent row of granules along the margins in 

 H. goldfussi (pi. 19, fig. 54) according to Strebel. In the 

 other species examined this is hardly noticeable (pi. 15, fig. 

 14, H. elizabetha) . At the angle of the mantle there are small 

 righgt and left neck-processes in all the species examined (pi. 

 19, fig. 51, H. goldfussi) . 



Pallial organs. The lung is long and narrow. Kidney very 

 narrowly triangular, being wider at the base, tapering ante- 

 riorly, slightly longer than the pericardium (pi. 27, fig. 37, 

 H. dalli x 4). There is apparently no secondary ureter. 



