1906.] NATURAL SCIENCES OF PHILADELPHIA. 157 



of ''bad letters." All authorities agree that such obvious typograph- 

 ical errors should be corrected. 

 Helicodiscus eigenmanni Pils. PI. VIII, figs 1, 2, 3. 



Nautilus, XIV, p. 41. August, 1900 (Beaver cave, near San Marcos, Texas). 



This fine species is easily recognized by its large size, the shell in 



all stages of growth being very much more robust than H. parallelus. It 



is sculptured with numerous spiral threads as in H. parallelus, and 



when fresh is pale yellow. Alt. 2, diam. 5 mm., with 5^ whorls. 



We took specimens in the drift debris of Sinking creek at San Mar- 

 cos, Hays county; on the Guadalupe river above New Braunfels, 

 Comal county; on the Hondo river, Medina county, and in the drift 

 of Devil's river, Val Verde county; Alpine, Brewster county. I have 

 seen specimens also from Calhoun county (Hubbard), Lee county 

 (Singley), and Navidad river bottom, Jackson county (J. D. Mitchell). 

 It has not been reported from any place out of Texas, and seems to 

 have about the same distribution as Holospira goldfussi. 

 Helicodiscus eigenmanni arizonensis n. subsp. PI. VIII, figs. 4, 5, 6. 



Shell larger than H. parallelus with 4^ to nearly 5^ whorls, the spire 

 flat or convex, the umbilicus wider than in parallelus or eigenmanni. 

 Surface closely and strongly lirulate spirally. Aperture oblique, lunate, 

 very small. 



Alt. 2, diam. 5 nmi., whorls 5^. (Fort Bowie.) 

 Alt. 1.5, diam. 4.6 mm., whorls 4^. (Cave creek canyon.) 

 Arizona: Fort Bowie (type locality); Bear Park and Cave creek 

 canyon, Chiricahua mountains; Huachuca mountains (Ferriss); Santa 

 Rita mountains (Ashmun). New Mexico: Florida mountains, Grant 

 county (Ferriss); Bland, Sandoval county (Ashmun) ; debris of Arroyo 

 Pecos at Las Vegas (Ckll.). 



Readily distinguished from H. parallelus when mature by the greater 

 size, with wider umbilicus, more whorls and proportionately smaller 

 mouth. Some specimens are two-toothed. H. eigenmanni has a 

 smaller umbilicus, whorls of markedly greater calibre and a larger 

 aperture. 

 Helicodiscus salmonensis (Hemphill). 



HeUcodiscu^ fimbriatus Wetherbv (salmonacca Hemphill), W. G. Binney, 

 Tliird Supplement to Terr. MoU., V, BuU. Mus. Comp. Zool., XIX, No. 4, 

 p. 189 (May, 1890). 

 Helicodiscus fimbriatus var. salmonensis Hempliill, in Binney, t. c, p. 220 



(May, 1890). 

 Helicodiscus fimbriatus Wetherby, var. salmonaceus Hemphill, Binney, 

 Fourth Supplement, Bull. Mus. Comp. Zool., XXII, No. 4, p. 177, pi. 3, 

 fig. 8. 

 Distinguished by the absence of spiral striae, according to Hemphill. 



