Lake Maxinkuckee, Physical and Biological Survey 67 



Most of the mussels of the lake are slightly parasitized, none 

 abundantly ; they contain a few examples of a small reddish Atax, 

 and a few Cotylaspis insignis. A small round-worm, somewhat 

 like a vinegar eel, was found very active in the intestine of one 

 specimen ; it was probably parasitic. 



Small irregular pearls or slugs are produced but they are of no 

 value. In some rivers this species produces an abundance of small 

 round pearls. Some of the pearl-bearing river specimens were 

 planted in the lake in 1912 to see if they would infect the lake 

 shells. The Lampsilis luteola of the rivers is a fair button shell, 

 but the Lake Maxinkuckee shells are too small and thin to have 

 much value. It is a remarkable fact that in Lake Pokegama, 

 Minn., L. luteola grows abundantly in shallow bottom among the 

 weeds, and there produces a handsome thick heavy shell, one indeed 

 concerning which the pearl button manufacturers are very enthusi- 

 astic, so much so that the shells at that distant point from the 

 market brought $22.00 per ton; in the summer of 1912, two car- 

 loads of these shells were shipped to Europe. 



Just why the Lake Maxinkuckee shells are not like the excel- 

 lent ones of Lake Pokegama remains as yet unanswered, but seems 

 to be largely a question of breed. It would certainly be worth 

 while to introduce the Lake Pokegama breed into Lake Maxin- 

 kuckee. 



Following is the result of the examination of various indi- 

 viduals of the Maxinkuckee and Lost Lake shells : 



Sample 25. L. luteola. Lost Lake, Sept. 7, 1908. Mussel 

 gravid. Length 100 mm., altitude 62 mm. ; diameter 33 mm. Live 

 weight 3| oz. ; shell If oz. Parasites — 7 free Atax among gills, 

 young Atax in gills and numerous Atax eggs on interior surface 

 of mantle. Food chiefly Microcystis aeruginosa, Botryococcus 

 braunii, Lyngbya aestuarii, Melosira, Navicula. 



Sample 26. L. luteola, Lost Lake, Sept. 7, 1908 ; mussel gravid ; 

 length 95 mm., alt.. 60 mm., diam., 38 mm.; live weight 3] oz. ; 

 shell 1| oz. Parasites, 7 free Atax in gills, and Atax eggs in the 

 mantle. Food — chiefly Microcystis aeruginosa, also Botryococc/'s 

 braunii, Navicula, Lyngbya aestuarii and Anuraea cochlearis. 



Sample 27. L. luteola, Lost Lake by Bardsley's, Sept. 7, 1908 ; 

 live weight 3| oz. ; shell H oz. ; length 97 mm., alt. 54 mm., diam. 

 33 mm. Parasites — 7 free Atax among gills ; many small red 

 eggs of Atax on inner surface of mantle. Food chiefly Microcystis 

 aeruginosa, Botryococcus braunii and Navicula. 



Sample 28. Lampsilis luteola, Lost Lake, Sept. 7, 1908. Live 



