THE NAUTILUS. 71) 



NOTE ON SOME NEW MEXICAN SHELLS. 



BY H. A. PILSBRY, 



Professor T. D. A. Cockerell recently sent n small box of fluvia- 

 tile debris containing, shells, obtained during the past summer by 

 Professor J. D. Tinsley at South Spring Creek, near Roswell, N. M. 

 The list of species follows: 



Polygyra terasiana (Moric.) Planorbis exacutus Say. 



Bifidaria pentodon (Say). Ancylus rivularis Say. 



Zonitoides minusculus (Binn.). Physa virgata Gld. 

 Carychhnn exiguum (Say). Paludestrina seemanni (Fflcl.). 



Limn tea humilis Say. Amnicola sp. 



Planorbis bicarinatus Say. Pisidium compression Prime. 



There was a single dead specimen of the Amnicola, which is prob- 

 ably a new species somewhat like A. micrococcus, but more conic. 

 With the shells were numerous minute bivalve crustaceans of the 

 Cypris type, and some of the Valvata-like larva-cases of Helicopsyche, 

 composed of much coarser materials than are chosen by our eastern 

 H. arenifera. 



AMONG THE UNIOS OF THE SABINE RIVER. 



BY L. S. FRIERSON. 



The Sabine River forms part of the boundary between Texas and 

 Louisiana. The Houston, East & West Texas Railroad crosses the 

 river at Logansport, a thriving village of about one-half mile in diam- 

 eter. This town derives its support from an immense saw-mill, 

 one of the largest in the world. It is worthy of a trip to see the 

 huge logs pulled about, and in a few minutes turned into finished 

 lumber, loaded into cars and ready to go unto the uttermost parts of 

 the world. 



But it was not lumber for which I took my trip to the Sabine, but 

 to describe the river and its inhabitants. This river flows through 

 and over immense sand banks. Its walls are fifty feet high, and 

 mainly of pure sand from top to bottom. 



At the time of my visit it was so low that even a fiat-bottomed 

 skiff could not be paddled up it. except here and there in pools. As 



