MOLLUSCA. 163 



in the spring. This species was found in al)undance wherever the 

 temporary swamps (18) were studied, on Sand Point, North and Stony 

 Islands, and around Rush Lake. It was also found, but in lesser 

 numbers, in protected marshes (7) and in Turtle Bay (8), on Sand 

 Point, in rock pools along the north shore of Stony Island (3), in the 

 creek portion and in the "dead waters" of the Pigeon River (23, 24), 

 in a sedge marsh (12), in perennial swamps (19) and in a county 

 drain (17) at Rush Lake; and in sand pools (6) along the beach at Hat 

 Point. 



Lymnaea palustris, var.— The majority of the specimens obtained 

 from a certain temporary swamp (18) on Sand Point are elongate, 

 small, little malleated, and have a very heavy internal callus on the 

 lip. A representative example measures: altitude 18mm., width 

 7.75mm. ^ aperture length 9mm., aperture width 4mm. An example 

 of the short, light-colored, Httle malleated specimens that were col- 

 lected from the rock pools (4) on Stony Island measures: altitude 

 18.25mm., width 9.5mm., aperture length 10.5mm., aperture width 

 6.5mm. Of some large, slender, and heavily malleated specimens 

 that were found in a temporary swamp (18) on Stony Island, an ex- 

 treme measures: altitude 31mm., width 11mm., aperture length 12.5 

 mm., aperture width 6mm. 



57. Lymnaea palustris, var. michiganensis Walker. — A consider- 

 able number of juvenile shells of this form were collected from a 

 temporary swamp (18) on Sand Point. A few young specimens ^yere 

 also obtained from the upper portion of the Pigeon River (23) and 

 from a large, perennial swamp on Sand Point (19). A number of 

 adult shells were found in an annual swamp near Rush Lake (18). 



58. Lymnaea palustris, var. zebra Taylor. — The striped form of 

 Lymnaea ■palustris was found abundantly in two of the temporary 

 swamps on Sand Point (18) and in shallow^ water in a sedge marsh 

 along the shore of Rush Lake (12). Most of the shells are striped 

 longitudinally, often with serrated or wavy stripes, and one specimen 

 from Rush Lake is spirally striped. 



59. Lymnaea reflexa Say. — This species was characteristic of the 

 protected sedge marshes of the Bay (7) just as Lymnaea palustris 

 was of the temporary swamps in this region (18). It was found in 

 great abundance in this habitat at Sand Point, Stony Island, and 

 Caseville. It was also collected in small numbers at Sand Point, in 

 Turtle Bay (8) and in a large perennial swamp (19); at Stony Island, 

 in a protected marsh on the rock}^ north shore (4) ; and at Caseville. 

 in the ox-bow pond of Pigeon River (22). 



60. Lymnaea reflexa, var.* — Some specimens obtained from the 



* Baker, H. Burrinatoii. Variations in Lymntea reflexa Say, from Huron County. 12tli 

 Ann, Kept. Mich. Acad. Sci., pp. 60-63. 



