1903.] NATURAL SCIENCES OF PHILADELPHIA. 765 



figured in Manual of Conchology, XI, PI. 17, fig. 24. Those from near 

 Victoria are similarly marked, but are smaller. Both have the hp 

 thickened and the mouth brown or purplish-bro-s\Ti inside, the tint 

 rather dilute in some specimens. 

 Drymaeus emeus (Say). 



Caiion 4 miles west of Victoria, Tamaulipas. Specimens like von 

 Martens' figures 7, 7a, of Plate 14 of the Biologia. This is far north 

 of all previous records. 



Drymaeus sulphureus (Pfr.)- 



Texolo, V. C. 

 Drymaeus hegewischi (Pfr.). 



Texolo, V. C. 

 Drymaeus dunkeri (Pfr.). 



Patzcuaro and Tzintzuntzan, Michoacan. 



XJROCOPTID^. 

 Microceramus mexicanus (Marts.). 



Man. of Conch. (2), XVI, p. 156, PI. 26, figs. 26, 27 (specimen from Diente). 



Around Victoria, Tamaulipas, and Diente, near ^lonterey, NueA'o 



Leon. This form is readily distinguishable from both M. concisus on 



the south and M . texanus on the north. It occurred in numbers, and 



is no doubt a widely spread and characteristic east Mexican species. 



Subgenus GYROCION nov. 



Slender cylindrelloid snails with the axis large, hollow and smooth, 

 apex smooth and apparently retained entire. Whorls extremely 

 numerous and narrow, some intermediate ones with a spiral lamella 

 within on the basal partition. Characters of the aperture unknown. 



This group is proposed for an imperfectly known snail which cannot 

 well be placed in any of the recognized genera, though it apparently 

 is related to Epirohia and Holospira. The former group differs b}^ its 

 rugose axis and in the absence of a spiral basal lamella. Further 

 examples of the complete shell and a knowledge of the dentition are 

 necessary for an adequate definition of the position of the group. 

 Epirobia (Gyrocion) mirabilis n. sp. PI. L, figs. 10, 10a. 



The shell is cylindric below, gradually tapering above to an entire 

 apex; composed of ver}- many narrow and strongly convex whorls; 

 light brown ; finely and closely costulate-striate vertically. The apex 

 is obtuse, smooth and rather globular; the following three whorls are 

 equal in diameter; the calibre of the shell then slowly enlarges until 



