166 MOLLUSC A. 



68. Planorbis hirsutus Gould.- — Specimens of this shell were ob- 

 tained in small numbers at Sand Point, ifrom the under-side of lily- 

 pads in Turtle Bay (8) ; on Stony Island, from lily-pads in the large 

 swamps (19) and from driftwood in a marsh along the protected rocky 

 shore (4) ; and in Rush Lake, off Dune Point (15). Some of the speci- 

 mens are quite strongly carinated, others show very little carination. 



69. Planorbis deflectus Say. — ^This species was not found so widely 

 distributed as the two preceding ones, but it was more abundant in 

 the localities where it was found. It was collected at Sand Point, 

 from decaying driftwood in the sedge marshes (7), and on Stony Is- 

 land, from lily-pads in the perennial swamps (19). 



70. Planorbis parvus Say.- — This shell appeared to be the most 

 abundant and widely distributed of the small planorbices in this 

 region, just as Planorbis trivolvis was among the larger ones. It was 

 found at Sand Point, on the under-side of lily-pads and driftwood in 

 Turtle Bay (8) and on decaying leaves in an annual swamp (18) ; in 

 the Pigeon River, among algae (21), on lily-pads in the ox-bow pond 

 (22) and in the dead water, (24); at Rush Lake, on the bottom off 

 Raymond's, Dune, and Fourth Points (14, 15, 16) and in a perennial 

 swamp (19); and near Little Oak Point, in an old stone quarry (20). 



Planorbis parvus, var. — A variation that was slightly carinate and 

 concave, above and below, was collected in a perennial swamp (19) 

 near Rush Lake. 



71. Planorbis parvus, var. walkeri Vanatta. — A single individual 

 of this form was found in a temporary swamp (18) near Rush Lake. 



72. Planorbis umbilicatellus Cockerell. — Single specimens of this 

 species were collected from temporary swamps (18) on Sand Point 

 and at Rush Lake. 



73. Planorbis crista (Linne). — A shell of this species was found 

 on the under-side of a lily-pad in a perennial swamp (19) on Stony 

 Island, and two others in the sedge marsh (12) at Rush Lake. 



Planorbis sp? — Some specimens, too young to identify, were found 

 in temporarv swamps (18) on Sand Point and near Caseville. 



74. Segmentina armigera (Say). — This species was obtained in 

 considerable abundance on Sand Point, from a perennial swamp (19); 

 on Stony Island, from a temporary swamp (18); and from Rush Lake 

 from both kinds of swamps (18, 19). An example measures: greater 

 diameter 7.5mm., height 2.75mm., aperture height 2.5mm., aperture 

 width 2.25mm. 



75. Segmentina crassilabris Walker. — This species was collected 

 in small numbers from driftwood in the upper portion of Pigeon 

 River (23) and from temporary swamps (18) near Rush Lake. A 



