Lake Maxinkuckee, Physical and Biological Survey 601 



by a muskrat, the tracks of which were in evidence. Another was 

 found November 27, partly devoured. Apparently the muskrat 

 occasionally catches one of these turtles or finds it torpid during 

 the winter season, and feed on it. At any rate, we found them 

 now and then (though not so frequently as we did the Painted 

 Turtle) lying on the ice, usually belly up, with the flesh chewed 

 out from the sides. The muskrats were not actually caught doing 

 the work, but, as it took us some time to catch them actually 

 catching mussels and cleaning out their shells, and as, on several 

 occasions, muskrat tracks, and no other, were seen coming to the 

 turtles, we are convinced we would have caught them at it if our 

 observations could have been longer continued. Probably the 

 muskrats pick up the turtles and lay them aside much as they 

 do shells they are unable to open, and after the turtles are frozen, 

 devour them. 



These turtles are often infested by leeches, which doubtless 

 cause annoyance at least. 



Like the Snapper, the Musk Turtle is frequently covered with 

 alg^ on the back, the algae often being quite long and thick. The 

 proportion of turtles covered with algse varies with the season and 

 conditions ; in early summer, before the scutes are shed, all or 

 nearly all the turtles would probably be covered; with the shed- 

 ding of the epidermal scutes the turtle comes forth clean of algae, 

 and bright in color. 



During the late summer and early autumn of 1906, many small 

 musk turtles were seen surrounded by a white halo which was con- 

 spicuous at a distance, very much resembling the general appear- 

 ance of Saprolegnia on fishes. It was found upon examination 

 that the white growth consisted of a dense growth of a stalked 

 branched protozoan, Opercularia. Later it was found that larger 

 musk turtles harbored considerable masses of the protozoan on 

 the plastron, this being frequently entirely covered, so that the 

 turtles were practically botanical gardens above and zoological 

 gardens below. Neither the alga nor the protozoan appears to do 

 the turtles any injury. The alga above may assist the turtle in 

 concealment; the protozoan below is self-supporting, feeding on 

 minute organisms. The turtles in the muddy waters of Lost Lake 

 are much more heavily overgrown than those of the clearer waters 

 of Lake Maxinkuckee. 



The Musk Turtle is a harmless creature and certainly does some 

 good as a scavenger. It should, therefore, be protected. 



So far as we are informed, it is never utilized as food by man ; 

 its small size and disagreeable odor preclude such a possibility. It 



