152 



PROCEEDINGS OF THE ACADEMY OF 



[March, 



the last whorl; it is less depressed, and the aperture is perceptibly less 

 broad, more roundly lunate. The differences seem sufficient to call for 

 subspecific separation. The Texan and Floridian areas of distribution 

 seem to be separated, so far as our present data 

 indicates. V. daUiana should be looked for along 

 the northern border of the Gulf. It is known now 

 from peninsular Florida only. 



Vitrea dalliana " and roemeri are much smaller 

 than V. hammonis, and seem to replace that in the 

 Austroriparian and Lower Sonoran zones. Wlien 

 originally described it was compared with Zonitoides 

 arhorea (Say), but it is not really related to that but 

 to the hammonis group. In fact V. hammonis, 

 hinneyana and dalliana form a group of very closely 

 related species. In a large number of V. dalliana 

 examined from several localities, the largest shell 

 measures, alt. 1.6, diam. 3.2, width of umbihcus 

 .75, aperture 1.4 mm. wide, 1.2 high. This shell, 

 from Osprey, Manatee county, Fla., is here figured. 

 The figures do not represent the fine and beautiful sculpture of the 

 surface. 



Fig. 9.— F. dalliana. 



Vitrea milium meridionalis n. subsp. 



Similar to V. milium but larger, diam. about 1.75 mm., with nearly 

 3^ whorls, the first one finely, distinctly Urate spirally, the last whorl 

 with obhque wrinkles much coarser than in milium, more or less an- 

 astomosing, and fine spiral striae, the latter distinct on the base. 



V. milium with the same number of whorls is smaller and more 

 finely wrinkled, and in Maine and Ohio shells spirals on the first 

 whorl are excessively weak or wanting, not deeply engraved to the 

 tip, as in Texas shells. 



Texas: San Marcos, in drift of Sinking creek, in the limestone hills; 

 along the Guadalupe river above New Braunfels (t^^^e locahty); 

 Hondo river, Medina county ; drift of Pecos river. (Pilsbry and Ferriss.) 



New Mexico: Cloud croft, Sacramento mountains (Viereck); Santa 

 Fe (Ashmun). 



Arizona: Huachuca mountains (Ferriss); Walnut Gulch near Jer- 

 ome (Ashmun), 



Specimens from Baldwin and Clarke counties, Ala. (C. B. Moore), 



" Zonites dallianus Simpson, Pilsbry, Proc. A. N. S. Phila., 1889, p. 83, pi. 3, 

 figs. 9-11. 



