MOLLUSCA. 173 



abundantly along the unprotected sandy shore of 8and Point (5), in 

 shallow water. A single specimen was also collected in a similar 

 locality off the shore of Stony Island. The beaks are considerably 

 eroded. A large specimen from Sand Point measures: length 66mm., 

 height 31mm., breadth 18mm. 



103. Lampsilis iris (Lea).- — A single specimen of this shell was ob- 

 tained from the lower portion of Pigeon River (21), in quite shallow 

 water. It measures: length 74mm., height 42mm., breadth 18mm. 

 The beaks are somewhat eroded. 



104. Strophitus edentulus (Say).— A single shell of this species 

 was found in about four feet of water off the south, protected shore 

 of Sand Point (7). It measures: length 83.5mm., height 43mm., 

 breadth 33mm.; the beaks are quite heavily eroded. 



105. Anodonta marginata Say. — This species was obtained in con- 

 siderable abundance in Rush Lake, in places where the bottom was 

 mucky (11), and off Dune Point (15), where the bottom was sand 

 with a very thin cover of marl. A representative example measures: 

 length 86mm., height 45mm., breadth 31mm. In mucky places these 

 shells buried themselves as has been described for Lampsilis luteola. 



106. Anodonta grandis Say. — A few specimens of the typical form 

 of this species were collected in the lower part of the Pigeon River 

 (21) and in the ox-bow pond off the river (22). The largest shell 

 measures: length 118mm., height 65mm., breadth 39.5mm. 



107. Anodonta grandis, var. footiana (Lea). — A single depaupe- 

 rate and deformed specimen of this form was obtained from the lower 

 portion of the Pigeon River (21) and three shells of the lake form 

 were collected from the unprotected sandy shore of Sand Point (5). 

 The largest of the latter measures: length 85mm., height 44mm., 

 breadth 33mm. The beaks are considerably eroded. 



108. Anodonta grandis, var. . gigantea (Lea). — This form was ob- 

 tained abundantly in Rush Lake, in places where the bottom was 

 mucky (11) or marly (13), or sandy, as off Raymond's and Dune 

 Points (14, 15).. It did not bury itself in the muck as did Anodonta 

 marginata and Lampsilis luteola. An average example measures: 

 length 115mm., height 63mm.. breadth 40mm. 



109. Anodontoides ferussacianus, var. subcylindraceus (Lea). — A 

 juvenile individual of this species was found on the unprotected north 

 shore of Sand Point (5). It was obtained in great abundance in the 

 lower portion of the Pigeon River (21) and in the ox-bow pond off 

 from it (22). A representative example measures: length 66mm., 

 height 32.5mm., breadth 25mm. 



110. Anodontoides ferussacianus, var. modestus (Lea). — This 

 species occurred in considerable abundance in the ox-bow pond (22) 



