279 



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

 dantly; they contain a few examples of a small reddish Atax, and a few 

 Cotylaspi^ 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 Lampailis 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 enthusiastic, so much so that the shells 

 at that distant point from the market brought $22.00 per ton; in the 

 summer of 1912, two carloads of these shells were shipped to Europe. 



Just why the Lake Maxinkuckee shells are not like the excellent 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 Maxinkuckee. 



Following is the results of the examination of various individuals 

 of the Maxinkuckee and Lost Lake shells : 



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

 gravid. Length 100 mm., altitude 62 mm.; diameter .3.3 mm. Live 

 weight 2% oz. ; shell 1% oz. Parasites: 7 free Atax among gills, young 

 At ax in gills and numerous Atax eggs on interior surface of mantle. 

 Food chiefly Microcystis aeruginosa; Botryococcus bratinii, Lyngbya 

 xsturaii; Melosira; Navicula. 



Sample 26. L. luteola. Lost Lake, September 7, 1908: Mussel 

 gravid: Length 9.5 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 Botryococcus 

 hraunii; Navicula; Lyngbya aestuarii; and Amiraea cochlearis. 



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

 Live weight 3^4 oz. ; shell IV^ oz., length 97 mm., alt. .54 mm., diam. 33 



