10 Observations on the Terrestrial 



Tachea hortensis, Miiller. 



This species has been found in abundance on several islands 

 from Casco Bay to Grand Menan. Mr. Fuller found them on one 

 of the extreme outer islands in Casco Bay in great profusion ; the 

 island is covered with a gTowth of wild dwarf peai-, on the branches 

 of which he found great numbers clinging. If this species is 

 really identical with the Tachea hortensis of Europe, it seems a 

 little singular that here it should only be found on islands frequently 

 barren and far out from the land, and that the supposed variety 

 hortensis only should occur, while in the old country they become 

 a nuisance in gardens. 



W. Thomson, in the Annals and Mag. Nat. His. Second Series, 

 Vol. 7, gives the dentition of Tachea nemoralis thus : number of 

 rows in lingual membrane 135, number of plates in a row 100, 

 total 13,500. We find the following in a full grown specimen of 

 Tachea hortensis from Maine : 116 rows, 65 plates in a row, total 

 7540. 



A tracing which Mr. Binney sends me of the buccal plate of 

 the European T. nemoralis is nearly identical with the buccal plate 

 of this species, while that of the European hortensis is quite 

 difierent. 



Buccal plate, (Fig. W,) strongly arcuate, having 

 five longitudinal ribs which notch both edges of the 

 plate,central rib largest, distinctly striated transversely. 



Lingual membrane, 116-32-1-32, central plate widen- 

 Fif]. 11. ing posteriorly, having one large denticle not as long 



as plate, first seven laterals unidentate, which gradually merge into irregularly 

 tridentate uncini. (PL 4, Fig. 12.^ 



The numbers on the cut Indicate their position from the central : owing to the compli- 

 cated form of each plate, the entire row is not drawn. 



Stenotrema monodon, Rackett. 



Found throughout the State, though not a common species. 

 Two or three specimens are generally found together. I have 

 frequently noticed them on trunks of trees four or five feet from 

 the ground. I have also found them in open pastures. In 

 confinement the animal remains within the shell, rarely moving 

 about. The minute hairy projections on the surface of this species 



