274 



No. Length mm. Alt. mm. Diam.mm. 



4 64.9 35.8 22.7 



5 67.0 36.8 20.9 



6 67.7 33.8 21.5 



No young shells were found, even the smallest appear rathev old. 

 The smallest three measure: 



Length mm. Alt. mm. Diam. mm. 



41.4 21.2 12.5 



38.9 21.5 12.5 



37.0 20.0 12.3 



For comparison with the lake shells, the dimensions are given of the 

 largest two shells found in Yellow River: 



No. Length mm. Alt. mm. Diam. mm. 



1 67.0 34.5 22.9 



2 64.0 33.5 21.0 



Only one gravid example was found; this was obtained at Lost Lake 

 bed September 7, 1908. 



Of all the species of mussels in the lake, L. iris has the best con- 

 nection, through scattered individuals along the Outlet, with the shells 

 of the Tippecanoe River, a few shells having been found almost through 

 the whole length of the Outlet. The Outlet shells, like those of the 

 rivers, are brightly rayed. The species is abundant in the Tippecanoe 

 River at Belong. A number of examples were noted in spawning condi- 

 tion there in late August and early September in 1908. Observations 

 in the Maumee River indicate that this species, L. parva and L. multi- 

 radiata, do not have exactly the same breeding season as many other 

 species of Lampsilif; {luteola, recta, ligamentina, etc.), but are some- 

 times fertilized in July, spawning in August and September. Being 

 small and an early developing species, it is probable that they have 

 somewhat different habits; indeed, it is possible that they have more 

 breeding seasons per year than the other species. 



The Tippecanoe mussels of this species were a favorite food of the 

 muskrat, and were killed in gi-eat numbers every autumn, the dead 

 shells being thickly strewn a,long the bank, or piled in heaps at the 

 bases of rocks which the rodent used as a feeding place. 



