284 



12. LdDipfiilis multiradiata (Lea). 



Not abundant in the lake; occasional shells are found along .-^hove, 

 and now and then they are encountered in the piles of shells where 

 muskrats have been feeding. A few living examples were found in the 

 mussel bed near the mouth of Norris Inlet and a few at Long Point bed. 

 In all hardly a dozen living examples were secured; of 563 shells taken 

 from a pile left by a muskrat at Long Point in 1907, only one was of 

 this species. This mussel, as it occurs in the lake, is not nearly so 

 attractive as river specimens, being dwarfed, and so deeply stained that 

 the rays are inconspicuous, being usually black or dull brown instead 

 of green. 



This species was found in unusual abundance in the Tippecanoe 

 River at Delong, and a considerable number was observed spawning dur- 

 ing the autumn of 1908. While spawning, this mussel is very conspic- 

 uous in its habits. It lies either on its back, or more usually with 

 the posterior end directly upward, and the showy edges of the mantle, 

 which are of a yellowish brown color, and cross-barred with narrow 

 lines which are continuous with the fine rays of the epidermis, look a 

 good deal like a small darter lying on the bottom. Long waving pennant- 

 like flaps, with showy black spots at the base of each are developed, 

 and this portion of the mussel is made still more conspicuous by reason 

 of periodic violent spasmodic contractions. 



In the Tippecanoe River near Delong this is one of the favorite 

 foods of the muskrat, and it must be difficult for them to hold their 

 own against that rodent. 



13. Micromya fabalis (Lea). 



Rare; previous to 1913 only one shell had been found; this was 

 picked up on the north shore of the lake in 1907. In 1913 several 

 shells, recently cleaned out by some animal, probably a muskrat, were 

 found at the wagon bridge. This species is fairly common in Tippecanoe 

 Lake and still more so in the Tippecanoe River at Delong, where it was 

 collected in shallow water near shore in rather stiff blue clay. It is 

 the smallest of our Unionidae. The white or bluish white nacre has 

 an exceedingly brilliant luster. 



Several other species of mussels have been recorded for the lake, 

 among them Quadrnla laclirymosa (Lea), Margaritana marginata Say, 



