56 MUSSEL FAUNA OF MAUMEE EIVER. 



men was seen at New Haven, Incl. We ourselves found none in 

 the Maumee, except at its very head. 



Ptyc'hohrancJvus phaseolus decreases in numbers and disappears at 

 the very hist near Miami, Ohio. Dwarf examples were found at 

 Put-in Bay. 



Ohovaria circidiis diminishes rapidly in numbers, and the last one 

 was found in the Auglaize Kiver at Defiance, Ohio. 



Lampsilis nmilUradiatus^ fairly well distributed in the upper part 

 of the river, wholly disappeared at Defiance. 



L. ligamentinus decreased in number more than in size, but 

 diminished considerably even in size. 



Truncilla sulcata, never very common, was not found below De- 

 fiance, Ohio. 



The following species increase in number or size, or both, with the 

 descent of the river : 



Quadrula pustidosa increases both in number and size until it is 

 fairly common below Grand Eapids, Ohio. 



Q. lachri/7)wsa first appears in the Auglaize a little above Defiance 

 and becomes quite common in the lower part of the Maumee and in 

 the canal. 



Unio gihhosus increases both in size and number and becomes one 

 of the most common forms in the lower part of the river. 



Anodonta imhecillis appeared in considerable numbers at the very 

 last, in the canal below the dam at Miami, Ohio. 



Ohliquaria ref-exa first appeared in the Auglaize River, near De- 

 fiance, and became fairly common below there; the same may be said 

 of Plagiola donaclforrnis and Plagiola elegims. 



Laiivpsilis gracilis shows considerable increase both in numbers and 

 size. The same may be said of Lampsilis alatiis, of which very few 

 were found at Fort Wayne, while it was abundant in the lower 

 stretches of the river. 



The following species are of about equal size and distribution 

 throughout the entire length of the river : 



Quadi'ula undidata was fairly common everywhere. It prefers a 

 solid bottom overlaid with a thin stratum of rather soft mud, and 

 wherever these conditions were encountered it was pretty sure to be 

 found. 



Symjjhynota costata was also fairly common everywhere; it in- 

 creased somewhat in size as we descended the river, the examples 

 found in the Auglaize being the largest obtained. 



Anodonta graiidis was nowhere abundant, but was found at nearly 

 every station. It prefers a soft muddy bottom. 



Lnmpsilis iris was rare everywhere, but was found all along the 

 river. 



