32 THE NAUTILUS. 



become stronger and channeled near the end of tlie nearly straiglit 

 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 whicli 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 R. D. WALKER AND WM. H. COOLIDGE, JR. 



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

 the late George Alexander Wheeloek, 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. Wheeloek spent almost his entire life 

 in Keene (181fi-l'J06) 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 graiium Say. 



Planorbis bicarinattis Say. Avinicola limosa Say. 



Planorbis campanulatus Say. Ujiio complanatiis Sol. 



Segmentina armigera Say. Alasmodonta undulata Say. 



Lymnea humilis Say. Lampsilis nasutus Say. 



Physu heterostropha Say. Anodonta cataracta Say. 



Aplexa hypnorum. Sphaerium rhoinboideum Say. 



Succinea ovalis Say. Sphaerium secure Prime. 



Polygyra albolabris 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. 



