Lake Maxinkuckee, Physical and Biological Survey 55 



4. ALASMIDONTA CALCEOLUS (Lea) 



Judging from the dead shells found scattered along shore, this 

 is not a particularly rare species in the lake. The shells were 

 found most abundantly along the north shore of the lake, although 

 they wore also found along the east and southeast portion and were 

 not infrequent between Arlington and Long Point. No living 

 examples were found. On account of its small size and its habits 

 this is a rather difficult species to find, even where common, ex- 

 cept under favorable conditions such as exceptionally low water, 

 when the mussels move about more or less. Nothing was therefore 

 learned of its habits in the lake. In the Tippecanoe River near De- 

 long, Ind., this species was rather common in stiff blue clay near 

 shore, and it is fairly abundant in Yellow River at Plymouth. 

 Here, although the dead shells were common, the living examples 

 were difficult to find until, during a period of very low water, they 

 began actively moving about and could be tracked down. The 

 species, which reaches an unusually large size in Yellow River, was 

 there found gravid in autumn (September and October). The 

 glochidia are of the Anodonta type, chestnut-shaped or rounded- 

 triangular in outline, with large hooks at the ventral tips of the 

 valves. 



5. FLOATER 



ANODONTA GRANDIS FOOTJANA Lea 



Although the genus Anodonta is generally regarded as the 

 "Pond-mussel" par excellence, the species of which might natur- 

 ally be expected to be at home in lakes and ponds and thrive in 

 such places even better than in rivers, the Anodontas of Lake Max- 

 inkuckee show, along with the river-species proper, the dwarfing 

 influence of the lake. Moreover, Anodonta is not, as one might 

 naturally expect, the most abundant mussel in the lake, but is out- 

 numbered in some beds at least, by both Lampsilis luteola and 

 Unio gibbosus. Its relative scarcity in some of the shore beds is 

 in part made up by its wider distribution in the deeper waters of 

 the lake than the others reach, and on its presence on the isolated 

 bars, where it was occasionally taken up by the dredge. 



On account of the great variability of Anodonta grandis and 

 the difficulty in distinguishing the various forms, particular atten- 

 tion was paid to this species as found in the lake, and the lake 

 specimens were compared with numerous examples from the neigh- 

 boring lakes and river. No Anodontas were found in the Tippe- 

 canoe River near Lake Maxinkuckee Outlet, and we were therefore 



