VALLONIA. 259 



Hel. tenuilabris WESTERLTJND, Vers. D. Naturf. Main, 1843, 

 p. 143 ; id. Fauna I, p. 15. SANDBERGER, Conch, der Vorvelt, 

 p. 841, t. 36, f. 16. 



Var. SAXONIANA Sterki. PI. 33, figs. 30, 31, 32, 33. 



I have seen no recent Asiatic specimens of the above. A fossil 

 form from Krsellwitz near Halle, A. S., Saxony, has been sent out as 

 tenuilabris, and is represented in figs. 30-33. The specimens are 

 remarkably well preserved, more or less transparent, with the epi- 

 conch preserved, and differs in some particulars from the above 

 description ; umbilicus at first rather narrow, (narrower than 

 drawn in fig. 31) surface rather finely and densely striate, hardly to 

 be described as ribbed ; peristome entirely without a lip ; the last 

 whorl is distinctly ascending before descending in front (figs. 33, 

 32) ; there is also no trace of a difference in color of the apertural 

 part and the balance of the shell. 



Alt. 1-f, greater diam. 3'l-3'3, lesser 2'4-2'6 mill. 



From this, it becomes evident that the two forms are different ; 

 and the Krsellwitz shell requires a name ; yet for obvious reasons it 

 is preferable to range it as a variety under V. tenuilabris. 



V. CYCLOPHORELLA Ancey, n. sp. PL 33, figs. 34-38 ; pi. 32, fig. 29. 



Shell rather widely umbilicated, more widely so for the last half 

 whorl, depressed convex above, grayish horn colored, translucent, 

 with small, crowded ribs bearing small membranes; nucleus with 

 indistinct revolving lines. Whorls 4, gradually increasing, with a 

 moderately deep suture, the last somewhat widening, distinctly 

 ascending before descending in front. Aperture very oblique, trans- 

 versely oval, with margins much approximating ; peristome somewhat 

 everted at the periphery and below, thin, without a lip. 



The ribs are comparatively very fine, about 60 on the last whorl, 

 and somewhat irregular (fig. 29.) 



Rocky Mts.; Colorado, Utah, Washington. 



V. cyclophorella ANCEY, MS. 



Jaw rather narrow (short), truncated at the ends, with rather 

 stout, irregular ribs, except near the ends. Kadula with 63 trans- 

 verse rows of 25 teeth ; 5 laterals ; on the first 2'3 marginals the 

 mesodont is little longer than the other cusps, on the following teeth 

 of the same size. 



