98 LAND AND FRESH-WATER SHELLS STEARNS. 



batus or schicdeanus were found, nor have I ever seen any, although I 

 have collected thousands of Bulhmdi in Texas," etc. 



The National Museum is indebted to Mr. Pilsbry for an example of 

 the original lot from Montague County, Texas (Mus. No. 1183G1), in 

 which the sculpture described by the author is so sharply developed, 

 that without intervening and connecting specimens it might well be 

 regarded as a new form. 



With his specimen and comments before me, I was led to examine 

 the large geographical series of dealbatns and related species, and found 

 that in certain examples from Texas (Mus. No. 26411) collected by Dr. 

 Shumard many years ago, the u])pcr ichorls of two, and nearly the whole 

 of the third, show this ribbing; in the first two the corneous ground 

 color prevails. In another lot, also from Texas, collected years ago by 

 General (then Lieutenant) Couch, U. S. Army, the specimens are unusu- 

 ally elongated (No. 2G415), and one of them exhibits conspicuous growth 

 lines. In two examples (No. 29G14), of rather delicate texture, the cor- 

 neous character and coloration dominates, with opaque longitudinal 

 streaks of whitish color; the upper whorls in these are ribbed. The 

 same also in four specimens (No. 30690) from Texas, collected by Lieu- 

 tenant Beale. In another tube (No. 31625) three of the eight specimens 

 are ribbed. Three out of eight examples from Leon, Texas (No. 26410), 

 exhibit this feature, and two out of five from Dallas, Texas (No. 26413), 

 have the same sculptural peculiarity. 



In specimens from Clifton, Texas (No. 30240), the upper whorls are 

 ribbed, and the ribbing continues down to and upon the upper part of 

 the basal whorl just below the suture. So in examples from San Felipe 

 Springs (No. 26569), collected by Lieutenant Beale, six of the seven 

 may be regarded as the variety ragsdalei. 



Mr. C. T. Simpson collected specimens in Limestone Gap, Indian 

 Territory (No. 101062), and four of the examples show distinct ribbing 

 on the upper whorls ; so also with specimens from Matamoras, Mexico 

 (U. S. Mus. No. 26407), of alternatns, two specimens, and others from 

 Tamaulipas, Mexico (No. 26566), of this last named species. 



A single example of the variety ragsdalei was collected by Mr. 

 Bailey, who detected it in a canon of the Rio Grande at Langtry, 

 Texas. B. ragsdalei suggests the Asiatic form B. ahyssinicus liup- 

 pel (1= B.fairhanhsi Blfd.), from Bombay, which not unlikely some- 

 times occurs with inconspicuous growth lines like the ordinary form of 

 dealbatns. When the })hysical peculiarities of the region inhabited by 

 dealbatus, alternatus, etc., are considered we may reasonably look for 

 a wide range of variation in form, size, sculpture, etc., and it is highly 

 probable that individuals, if not colonies, with more striking charac- 

 teristics thau any yet collected, will sooner or later be discovered. 



