766 PROCEEDINGS OF THE ACADEMY OF [DeC, 



the cylindric portion has a diameter of 2.5 mm. The hollow central 

 axis is nearly one-third the diameter of the shell, and is smooth. In 

 the lower part of the tapering portion, a low lamella revolves in the 

 middle of the floor or basal wall of the whorls. Length of the fragment 

 of the tapering portion figured 6 mm.; whorls 17. Length of cylindric 

 fragment 4.2 mm. ; whorls about 5^. 



Diente, near Monterey, Nuevo Leon. Types No. 85,914, A. N. S. P., 

 two fragments collected by S. N. Rhoads. 1903. 



PUPID^. 



Pupoides marginatus (Say). 



Topo Chico, near Monterey, Nuevo Leon. Abundant. 

 Bifidaria contracta (Say). 



Texolo, V. C. (Rhoads.) Hitherto known from only two places in 

 Mexico, Orizaba, V. C, and Yautepec, Morelcs, collected by the Heil- 

 prin expedition of 1890. 



Bifidaria prototypus Pils. PI. L, figs. 7, la. 



Proc. Acad. Nat. Sci. Phila., 1899, p. 400. 

 The angular and parietal lamellae are more separated than in any 

 other species of the typical group of Bifidaria. 



Bifidaria pellucida hordeacella (Pils.). 



Proc. Acad. Nat. Sci. Phila., 1900, p. 594. 



Antigua, V. C. ; canon 4 miles from Victoria, Tamaulipas. 

 Bifidaria curvidens (Old.). 



Canon 4 miles west of Victoria, State of Tamaulipas. 



This species is new to the Mexican fauna. 

 Strobilops strebeli (Pfr.). 



Diente, near Monterey, Nuevo Leon. 



ZONITID^. 



Omphalina martensiana n. sp. PI. XLVIII, figs. 7, 7a, 76. 



Shell depressed, shaped about like 0. lucubrata Say; umbilicate; pale 

 green with a broad maroon band at the periphery, another below the 

 suture, leaving a pale-green band above the periphery, visible on the 

 whorls of the spire just above the suture, the first two whorls greenish; 

 the base, inside the peripheral maroon band, is also green. Surface 

 glossy, sculptured above with almost regularly spaced radial grooves 

 in harmony with the lines of growth, the base marked with growth- 

 wrinkles; between the radial grooves there are fine, sparse, forwardly- 

 descending, very minute raised lines, which on the base are more 



