The Nautilus. 



Vol. IV. SEPTEMBER, 1890. No. 5. 



BEMARKS ON CERTAIN GONIOBASES. 



BY H. A. PILSBRY, 



The typical Goniobasis pleuristriatus of Say is a shell of the gen- 

 eral form of Gon. virginica ; and like the variety multilineata of 

 that shell, it is encircled by numerous fine raised stria. It has been 

 collected in a number of the small rivers in Texas north of the Rio 

 Grande, the northermost being that beautiful stream, the Guadaloup 

 River, in Comal County.' Thomas Say described the shell in the 

 Nexo Harmorty Disseminator in 1829, — Say at that time being still 

 connected with that luckless company of socialists at New Harmony, 

 Indiana. 



In the Comal Creek, at the German colony of New Braunfels, the 

 the writer found very numerous specimens of a variety which wholly 

 lacks spiral strife, and has low, subobsolete longitudinal folds. 

 There is a single carina on the whorls of the spire. Specimens of 

 this variety were distributed by me several years ago under the name 

 of " Goniobasis comalensis ; " which name I now propose to use for 

 this variety. In the absence of a figure, I will be glad to send spec- 

 imens to any student of the Melanians who will apply to me. My 

 friend, Mr. J. A. Singley, has also collected specimens at New 

 Braunfels. This melanian is notable for the fact that its range is 

 wholly sundered from the rest of the family by the numerous rivers of 

 central and eastern Texas, draining into the Gulf, and without a sin- 

 gle species of the family Strepomatidse. The great extension of the 

 Gulf during past ages, up the Mississippi valley, shows the Texan 



