42 University of Michigan 



Pisidium variabilc brevius Sterki. Habitats : 7, 27m. 

 Pisidium vesiculare Sterki. Habitat 7m. 

 Pisidium sp. ? Habitat 34; unidentified. 



Unionidae 



Fusconaia ruhiginosa (Lea). Habitats: 31, 33. River spe- 

 cies; majority with beaks slightly eroded, but remainder of 

 epidermis with satin-like luster. One specimen with salmon- 

 pink nacre; July i, gravid specimens with bright crimson 

 embryos. Largest shell: 1. 82.5 mm,; alt. 57 mm.; w. 38.2 

 mm. ; smallest : 1. 62.5 mm. ; alt. 46.3 mm. ; w. 30.9 mm. 



Amhlema undulata (Barnes). A single dead specimen was 

 brought in from a small stream connecting Hamilton and 

 Louis lakes, about two miles southeast of Waucedah : 1. 114.5 

 mm.; alt. 84.1 mm.; w. 41.2 mm. 



Elliptio gibbosiis (Barnes). Habitats: 31, 33, 35. River 

 species. Specimens larger than in similar streams in southern 

 peninsula; largest: 1. 122.7 mm.; alt. 58.7 mm.; w. 36.6 mm. 

 July I, some specimens with gills padded with yellowish 

 embryos. 



Alasmidonta marginata Say. Habitats: 29, 33. Specimens 

 from sandy places with beaks little eroded ; those from rock 

 dam with beaks much eroded, and with a tendency to be 

 deformed, probably on account of having been often broken 

 against the rocks. One of the former: 1. 81.3 mm.; alt. 44.3 

 mm. ; w. 33.2 mm. 



Alasmidonta calceohis (Lea). Habitats: 10, 32, 33. Larg- 

 est specimen: 1. 49.1 mm.; alt. 29.9 mm.; w. 19.8 mm.; beaks 

 considerably eroded. 



Strophitus edenttdus (Say). Habitats: 31, 33. Two speci- 

 mens : beautiful and well developed ; dark olive-green in color 

 broken into stripes with an orange-yellow background near 



