FRESII-WATER MUSSELS. 



99 



summarize as follows the results of observations of mussels in lakes of Indiana and else- 

 where : 



Generally speaking, lakes and ponds are not so well suited to the growth and development of mussels 

 as rivers are; the species of lake or f)ond mussels are comparatively few and the individuals usually 

 somewhat dwarfed. Of about 84 species of mussels reported for the State of Indiana, only about 24 are 

 found in lakes, and not all of these in any one lake, several of them bat rarely in any. Of the 24 species 

 occasionally found in Indiana lakes, but 5 are reported only in lakes, and only 3 or 4 of the species com- 

 mon to both lakes and rivers seem to prefer lakes. 



Characteristic species of mussels of inclosed lakes of upper Central States are named 

 in the following table (4), and it may be remarked that the fat mucket and the floater 

 are easily predominant over all others. 



T.\BLB 4. — Characteristic Mussels op Lakes of Upper Centra:, States. 



^ Coker. R. E- (unpublished notes). 



^ Wilson and Danglade (1914). 



e Clark and Wilson (1912); Wilson and Clark C1912): and Evermann and Clark (1918). 



While, as has been previously indicated, the plains streams, such as the Red River 



or the Missouri, with their ever-changing banks and bottoms and silt-laden currents, 

 present conditions entirely unfavorable to mussels, yet the oxbow or cut-off lakes adja- 

 cent to them may offer favorable habitats for several species of mussels (Isely, 1914, and 

 Howard, unpublished notes). 



The sand shores of the Great Lakes to a depth of 8 feet are virtually barren of ani- 

 mal life (Shelford, 1918, p. 26). Fresh-water mussels are found in these lakes, chiefly, 

 it appears, in the shallower bays, where they sometimes manifest a vigorous growth. 

 They have not been used commercially to any extent, and probably few possess shells 

 of a size and quality rendering them suitable for button manufacture. 



In a biological examination of Lake Michigan in the Traverse Bay region, Ward 

 (1896) encountered 9 species of mussels, all of species generally possessing relatively 

 thin shells, while Reighard (1894) reported 20 species and subspecies from Lake St. 

 Clair, of which the following 8 were described as abundant : 



Pink heel-splitter, Lampsilis alata (Say). 

 Thin niggerhead, Quadnda coccinea (Conrad). 

 Spike, Unio gibbosus (Barnes). 

 Mucket, Lampsilis ligamentina (Lamarck). 



Lampsilis nasutus (Say). 



Black sand-shell, Lampsilis recta (Lamarck). 

 Pocketbook, Lampsilis ventricosa (Barnes). 

 Floater, Anodonta grandis (Say). 



A more extensive list of mussels from Lake Erie and the Detroit River is given by 

 Walker (1913), the list including 39 species of 15 genera. Since the great majority of 

 the species named are those that normally possess thin and fragile shells, it may be 



