18 PROCEEDINGS OP THE ACADEMY OF 



Cyclas sulcata Lam. (similis Say.) Lakes. Common. 



? River. Rare. (nov. sp) ? Rare. 



striatina Lam. (edentula Say.) Canal and rivers. Common, 

 transversa Say, Canal and rivers. Smaller than from the west, 

 rhomboidea Say. (elegans Ad.) Lakes. Rare, 

 partumeia Say. Stagnant waters. 



occidentalis Prime. Boggy streams and meadows. Plenty. 

 Pisidium virginicum Bgt. (dubium Say.) River. Not very plenty, 

 abditum Hold. Stagnant waters. Plenty, 

 compressum Prime. Rivers and small streams. Not rare, 

 equilaterale Prime. River east of Herkimer. Rare, 

 ferrugineum Prime. River and lakes, 

 ventricosum Prime. Lakes and stagnant pools. 

 Paludina integra Say. Canal and river. Very plenty in canal, 

 decisa Say. " " Very plenty in river, 



rufa Raid. " " Not plenty. Recently introduced. 



Melaniasubularis Lea. " " Common, 



exilis Raid. " " " 



virginica Say. Canal. Recently introduced. Not plenty. Local. 

 Amnicola limosa Say. Canal and river. Plenty. 



lustrica Say. " " Plenty in river, 



pallida Lea. Lakes. Not very plenty. 

 tenuipes ? Raid. Lakes. Not very plenty. 

 Valvata tricarinata Say* Mohawk river plenty. Canal less plenty. 



var. simplex of tricarinata Say, in Thompson's Vermont shells. 



Whorls round, simple, (inornate) ; apex elevated ; umbilicus 

 wide and deep ; epidermis blue, varying to brown, but not green, 

 nor iridescent, 

 sincera Say. Lakes. Very rare. 1 to 1000 of the above. 

 Lyransea elodes Say. Canal, ditches, pools, &c. varieties emarginata and catas- 

 copium, I have ascertained, may be produced from the eggs of 

 elodes, by change of station, 

 desidiosa Say. Stagnant pools, margins of streams and lakes, 

 humilis Raid. ? " (i " " " 



umbilicata Adams " " in wood lots. (is not caperata Say.) 



gracilis Jay. Schuyler's lake, Otsego Co. Plenty, 

 appressa Say. Little Lakes. A single dead shell observed, 

 columella Say. Lakes. Not abundant nor large. 

 Physa heterostropha Say. Everywhere in pools, lakes and small brooks, 

 ancillaria Say. May be a var. of preceding. Rivers, very rare, 

 hypnorum Drap. Stagnant pools. Small and rare. 

 Planorbis trivolvis Say. Common. 



bicarinatus Say. Common. In some localities, (lakes) white, 

 campanulatus Say. Lakes. Less common than the preceding, 

 armigerus Say. Stagnant waters. Common, 

 hirsutus Say. Lakes. Rare, 

 exacutus Say. Lakes. Very rare, 

 parvus Say. Stagnant waters. Very plenty. 

 Ancylus tardus Say. Mohawk river. Common on stones and Uniones. 

 parallelus Raid. Lakes. Common on water plants, 

 fuscus Adams. Lakes or waterfalls. Less abundant. 



* A variety occurs in Little Lakes, which presents much diversity of carination, some 

 specimens being almost entirely destitute of carinas, but retaining the characteristic iri- 

 descent green tinge. Those specimens in which the carinas are obsolete have the upper 

 surface of the whorls flattened, and the spire somewhat depressed. The conclusions of 

 authors, who suppose these varieties run into the following, are erroneous. 



[Jan. 



