104 Till-: NAUTILUS. 



Zonitoides arboreus Say. Common everywhere. 



Zonitoides exiguus St i m p. Fairly common. 



Zonitoides milium Morse. Quite rare. Woodland. 



Pyramidula ahernata Say. Common. 



Pyramidula alternata alba. One living specimen obtained in the 

 north of Woodland. 



Pyramidula striatella Anth. Plentiful. 



Pyramidula striatella^ var. Shell greenish-white, animal nearly 

 white. Can this lie Patula cronkhitei Newc? It is about the same 

 si/e as P. striatella. 



Pyramidtda asteriscus Morse. Caribou, Woodland and Madawaska 

 Lake. Rare. 



Helicodiscus lineatus Say. Widely distributed, nowhere abundant. 



Panctum pygmatum D r ap. Hare. 



Sphyradium edentulum Drap. Well-distributed. 



Succinea obliqua Say. Common everywhere. 



Succinea urn/is Old. 



Succinea avara Say. Common in wet places on lake shores and 

 river fiats, together with S. oralis. 



Carychium exiguum Say. Yer\ abundant in wet places every- 

 where. 



Carychium exile Lea. Not common; found with O. exiguum. 



Aplexa hypnorum Linne. In ditches along the roads in three dif- 

 ferent places in Woodland; specimens abundant. 



Physa heterostropha Say. Common in all streams. 



Physa ancillaria Say. Only seen at Square Lake Inlet. 



Lenmcea emarginata Say = ampla Mighels and Limncea emarginata 

 Mighels, Linn. From Cross Lake, Square Lake, Portage Lake, Fish 

 River, Saint John River, at Fort Kent and Aroostook River. 



This is an extremely variable species, Caribou individuals differ 

 greatly in every locality. 



Limncea desidiosa Say. Aroostook River, Caribou stream, Salmon 

 Brook. 



Limncea humilis Say. Common in damp places and ditches along 

 the roads. 



Planorbis trirolvis Say. Common in Barren Brook, Caribou. In 

 Caribou Lake, Washburn, and in nearly i\evy small lake I have 

 seen in Aroostook county, line specimens can be obtained. 



Planorbis campanulatus Say. Cross Lake, Square Lake, Eagle 

 Lake and Portage Lake. 



