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with incrustations of marl. It is principally this species which has asso- 

 ciated with it the little water-beetle, Stenelmis snlcatus Blatchley. At 

 Long Point, where L. luteola is the most common mussel, examples of the 

 peculiar Lost Lake form are rather frequent. In comparing sets of 

 shells from the various mussel beds of the lake, Long Point, Farrar's 

 and the Norris Inlet beds, it was noted that the mussels of each bed, 

 as one approached the upper portions of the lake, averaged somewhat 

 smaller. 



As regards food, movements, reproduction, etc., L. luteola does not 

 differ greatly from the other mussels of the lake with the exception that 

 it appears to be considerably the most active species in the lake. A 

 few more were observed moving about during the winter of 1900-1901. 

 The deep water individuals rarely move about at all. In the autumn of 

 1913 the migration of those near shore into deep water was strikingly 

 shown in a series of numerous furrows, with a mussel at the deep 

 water end and extending from shore outward near Long Point. 



As with the other mussels of the Lake, reproduction is a rather 

 inconspicuous phenomenon, not attended with the marked display com- 

 mon in the larger river examples. Of 252 examples collected at Long 

 Point, October 17, 1907, 25 contained glochidia in the gills, some being- 

 very full and much distended. One was found gravid May 24, 1901, 

 and on August 22, 1906, some in Lost Lake appeared to be about ready 

 to spawn. 



The young of this species were found rather frequently in the lake, 

 much more frequently, indeed, than any other kind. The smallest ex- 

 amples were obtained while seiving sand for Sphaeriums at Long Point. 

 These young mussels live buried in the fine sand near shore. Specimens 

 up to about a half-inch long are very crinkly, being covered with narrow 

 elevated parallel ridges, generally five in number, each consisting of two 

 open loops placed end to end, the sides of the loops being roughly 

 parallel with the ventral margin of the shell; the ends where they join 

 form a sharp curve upward toward the umbone. These double loops are 

 followed by a number of broken iriegular ridges. The markings just 

 described persist on the umbones of the older shells until eroded away. 

 The half grown shells are beautifully rayed with green on a whitish 

 background. As the shells grow older they become gradually stained 

 a deep uniform brown, obscuring the rays. 



