NOTES ON DISTRIBUTION OF SHELLS.— NO. II. 681 



CONCHOLOGY. 



NOTES ON DISTRIBUTION OF SHELLS.— NO. II. 



BY F. A. SAMPSON, FT. WORTH, TEXAS. 



The present mild winter doubtless gave a better opportunity for finding liv- 

 ing shells at Ft. Worth, than would often occur at New Year, but with butter- 

 flies and moths flying, one would naturally expect to find shells still crawling or 

 lightly covered. The country around is generally prairie, but along the Trinity 

 river and other streams, there is more or less bottom land of post-pliocene forma- 

 tion, and bordering these streams are bluffs more or less rocky, and in places 

 about one hundred feet in height, the rock exposures and the prairies all being of 

 the cretaceous period. 



Of the shells found by me around the town, and on trips in two directions 

 about ten miles each, I make the following notes: 



I Mesodon roemeri Pfr. Found at all stations near timber, both on the 

 bluffs and in the bottoms in considerable numbers, and bunched together as if 

 for the purpose of imparting warmth to each other. Under one small log in the 

 Trinity bottom I obtained over fifty mature live specimens. I could detect no 

 difference in those found on the bluffs from those on the lower grounds, but the 

 shells all differ considerably from the same species at New Braunfels, Texas, being 

 larger in size, of deeper color, and uniformly open umbilicus. I found a single 

 albino. 



2. Polygyra texasiana, Moricand, was quite plenty in places in the river 

 bottom, under stones, logs and in the ground where brush and leaves were lying. 

 Binney in his Land Shells of North America, gives the size of this species as lo 

 mm., and says that there is a larger size with a brown band above the periphery. 

 The specimens here, however, are from 8 to lo mm. and all have the brown band 

 more or less distinct. Through the shell the animal shows irregular black spots, 

 the last whirl having a line of them, sometimes continuous, running diagonally 

 through nearly one revolution. In some the spots are quite large and in others 

 small. The eye peduncles are deep black, and from their bases are two bands of 

 black down the neck and body, the remaining parts being a uniform light color, 



J. Polygyra mooreana, W. G. Binney, was not plenty, principally on the bluffs. 

 Less than half the shells were white, but those of horn color appeared to differ 

 in no respect except in the color of the shell. The spots showing through the 

 shell were not so large or so black as in the last species. The head, neck and 

 body were a uniform dark brown, and the eye peduncles still darker. Al 



