52 THE NAUTILUS. 



A NEW TEINOSTOMA. 



BY HENRY A. PILSBRY. 



Teinostoma Hidalgoana n. sp. 



Shell orbicular, depressed, solid, bright, bluish-white. Spire very- 

 low, wide-conic, the apex acute. Whorls 2], hardly convex, the 

 last large, rounded at periphery, depressed beneath ; on its latter 

 third the periphery descends toward the base, and immediately 

 behind the lip is decidedly pinched into a short rounded keel. Sur- 

 face closely engraved throughout with spiral Hues of close, fine 

 stippling or puuctation. Aperture oblique, rounded, except for the 

 straight parietal wall; peristome continuous, the outer lip thick, 

 blunt, strengthened outside by a heavy rib or collar a short distance 

 behind the edge; parietal wall bearing a low nodule or tooth near 

 its upper termination. Parieto-umbilical callus heavy, deeply and 

 coarsely pitted all over, forming a rounded lobe over the umbilical 

 tract and a band in front of the parietal edge of peristome proper. 

 Alt. 2, diam. 3'2 mm. 



Singapore (Dr. S. Archer !). This exq uisite species is respectfully 

 dedicated to Dr. J. G. Hidalgo, of Madrid, author of numerous valu- 

 able contributions to malacological science. 



One specimen of the type lot is much smaller than the others (diam. 

 2 mm.), but in all other respects exactly resembles them, and has the 

 lip of a fully mature shell. 



NOTES ON THE SMALLER AMERICAN PLANORBES. 



BY E. G. VANATTA. 



Including the species put in the sub-genera Menetus and Gyraulus 

 by Binney in " Land and Fresh-water Shells of the United States." 



The smaller species of Planorbis are, as a general rule, found on 

 leaves and sticks in small ponds and springs. 



The Western Slope species are centervillensis, operctilaris, opercu- 

 laris var. oregonensis and culfioglyptiis. 



P. alabamensis Pils. has so far been found only in Woodville, 

 Alabama, and Grove, Cooper River, S. C. 



P. sampsoni has been found hitherto only in Pettis and Henry 

 Co., Mo., and Athens, 111. 



