MOLLUSCA. 159 



has the sutures enough impressed to be referable to the form vermela; 

 it measures: length 9.5mm., width 5.25mm., aperture length 5.75mm., 

 aperture width 3.25mm. 



35. Succinea avara, var. vermeta (Say). — Specimens of this form 

 were obtained from the sand beach (34) on North Island and, as men- 

 tioned above, from a sand pool (6) near Little Oak Point. 



Pupillidae. 



3C. Strobilops virgo (Pilsbry). — ^This species was found in small 

 numbers among leaves and under logs in swampy and dry woods (38, 

 39) near Rush Lake, and among leaves gathered under a rock ledge at 

 Hat Point (27). 



37. Bifidaria contracta (Say). — This shell was, next to Bifidaria 

 tappaniana, the most abundant and the most widely distributed 

 species of the genus in the region studied. Specimens were found not 

 uncommonly in damp places on Sand Point (26), on the sand beach 

 along the south shore of North Island (34), in dry meadow-flats along 

 the Pigeon River (36), in wet and in high woods (38, 39) and in a 

 damp meadow along a cedar thicket (40) near Rush Lake. It was 

 found most abundantly around Rush Lake, under fallen logs in quite 

 dry woods on clayey soil. 



38. Bifidaria corticaria (Say). — ^This species was c^uite rare in the 

 region studied. A few specimens were found near Rush Lake, under 

 decaying logs and among fallen leaves in wet woods (38) and under 

 the bark of a fallen log in a quite dry patch of woods (39) just inside 

 of the sand dunes. It seemed to prefer a wet, rich habitat. 



39. Bifidaria pentodon (Say). — ^This shell was not rare in wet 

 places on Sand Point (26), under fallen logs and among decaying 

 leaves, and in similar places in both swampy and high woods (38, 39) 

 in the clay region around Rush Lake. 



Bifidaria sp? — A few juvenile pupiform shells, probalily Bifidaria 

 pentodon, were found among leaves around the bases of trees in a wet 

 woods (38) near Rush Lake. 



40. Bifidaria tappaniana (C. B. Adams). — ^This species was the 

 most widely distrilmted and abundant species of the genus in this 

 region. It was quite abundant under driftwood and decaying sedges 

 along the sandy, middle beach (25) and among fallen leaves on the 

 border of a swamp (26) at Sand Point, on the sand beach on North 

 Island (34), under driftwood on both swampy and dry creek flats 

 (35, 36) and in woods (37) along the Pigeon River, and under fallen 

 logs in swampy woods (38) and in a moist meadow along a cedar 

 thicket (40) near Rush Lake. 



4L Vertigo ovata Say. — ^This species was collected in numbers 



