TIIF. NAUTILUS. 105 



Planorbls bicarinatus Say. Aroostook River. Fish River and 

 Saint John River. 



Planorbis bicarinatus aroostookensis Pils. East branch of Salmon 

 Brook, Woodland, and Caribou stream, in Caribou. 



Planorbis hirsutus Gld. Common and widely distributed. 



Planorbis deflectus Say. Salmon Brook Woodland, rare ; Portage 

 Lake. 



Planorbis parvus Say. Common in brooks and lakes. 



Planorbis exacutus Say. Portage and Square Lakes ; rare. 



Planorbis crista Linne. var. cristata Drap. Barren Brook, Cari- 

 bou. This species was recorded in The Nautilus, Vol. X, page 

 117, by Mr. Bryant Walker as P. naulileus Linne. Mr. A. W. 

 Hanham, on page 130, and Geo. W. Taylor, on page 139 of the same 

 volume use the name of P. nautileus. Dr. v. Sterki and Prof. II. 

 A. Pilsbry say " it is Planorbis crista Linne. var. cristatus Drap. 

 It occurs in northern Europe." 



Ancylus rivularis Say. Caribou stream, Collin's Millpond, very 

 large specimens. 



Ancylus parallelus Ilald. Cross Lake and many smaller lakes 

 and streams. 



Ancylus f Madawaska River, New Sweden. 



Ancylus tardus Say. Aroostook River, Caribou. 



Ancylus borealis .' Morse. Saint .John River, Fort Kent. Mr. 

 Bryant "Walker say-* it is identical with this rare form. 



Valvata tricarinata Say. Little Madawaska River, New Sweden 

 and the Fish River Lake-. 



Valvata sincera Say. Dredged in the Fish River Lakes. 



Campeloma decisum Say. Widely distributed throughout Aroostook 

 and Fish Rivers. Four young sinistral shells were taken from a nor- 

 mal dextral female from Portage Lake. 



Amnicola limosa Say. Common everywhere, and very variable in 

 form. In my former article in The Nautilus, Vol. xi.. p. If, it is 

 called Pomatiopsis. 



A- Oincinnatiensis Lea. 



Ohio complanatus Sol. Lakes and streams ; common. 



Margaritana margaritifera Linne. Aroostook River. 



Margaritana undulata Say. Lakes and rivers. 



Anodonta fragilis Lam. Generally distributed, some very large 

 specimens in the muddy bottom of Salmon Brook Lake. Perham. 



