40 Observations on the Terrestrial 



Alexia myosotis, Drap. 



Found in the interstices of a sea wall in Poi-tland Harbor, at 

 low tide. 



Lingual membrane having fifty-one plates in a row, central plate wide, nar- 

 rowing anteriorly, having one short rounded denticle, laterals comprising half 

 the number of plates in a row, merging into uncini, laterals having one short 

 denticle, uncini bidentate. (PI. 10, Fig. 100.) 



MELAMPIN^. 



Melampus bidentatus, Say. 



Mr. Fuller has found a few dead specimens of this species 

 several miles west of Portland. Mr. A. E. Verrill states that he 

 found this species at Anticosti, in the Gulf of St. Lawrence. 



LIMNJSID.^. 



PLANORBINJEl. 

 Planorbis lentus, Say. 

 Not common. 



Helisoma bicarinatus, Say. 

 Abundant in all parts of the State. 



Helisoma trivolvis, Say. 

 Found by A. E. Verrill at Norway, Maine ; it has also been 

 found in one or two other places in the State. 



Planorbella campanulatus, Say. 



Found in abundance in certain localities ; not nearly as common 

 as the preceding species. 



Planorbula armigepus, Say. 



Generally diffused throughout the State, though not a common 

 species. 



