32 THE NAUTILUS. 



become stronger and channeled near the end of the nearly straight 

 canal ; aperture white, within purplish ; outer slightly thickened, not 

 reflected, smooth within posterior angle of the aperture grooved 

 and produced a little, with a subsutural obscure callosity on the 

 body which elsewhere has the surface smoothly erased, edge of the 

 pillar with one faint and one very strong marginal fold ; operculum 

 normal. Alt. of shell 19, of last whorl 13.5, of aperture 10, max. 

 diam. 8.0 mm. Found in crevices of the rocks a little below low- 

 water mark. 



MOLLUSCA OF KEENE, NEW HAMPSHIEE. 



BY K. D. WALKER AND WAI. H. COOLIDGE, JR. 



The shells that comprise this list were found in Keene, N. H., by 

 the late George Alexander Wheelock, and form a small part of the 

 extensive general collections which he made. The list is perhaps 

 worth publishing as local data in regard to the shells of Keene and 

 the surrounding regions. Mr. Wheelock spent almost his entire life 

 in Keene (1810-1906) investigating the natural history of Monad- 

 nock. The determination of the species is through the kindness of 

 Mr. Charles W. Johnson. 



Planorbis parvus Say. Lyogyrus graimm Say. 



Planorbis bicarinatus Say. Anmicola limosa Say. 



Planorbis campanulatus Say. Unio complanatus Sol. 



Segmentina armigera Say. Alasmodonta undulata Say. 



f,ymnea humilis Say. Lampsilis nasutus Say. 



Physa heterostropha Say. Anodonta cataracta Say. 



Aplexa hypnorum. Sphaerium rhomboideum Say. 



Succinea ovalis Say. Sphaerium secure Prime. 



Polygyra nlbolabris Say. Sphaerium pnrtumeium Say. 



Polygyra fraterna Say. Sphaerium simile Say. 



Zonitoides arboreus Say. Pisidium variabile Prime. 



Pyramidula cronkhitei anthonyi Pisidium compressum Prime. 

 Pils. 



These specimens are in the Thoreau Museum of Natural History, 

 Middlesex School, Concord, Massachusetts. 



