ORTMANN: monograph of the naiades of PENNSYLVANIA. 259 



Soft parts (See Ortmann, 1912, p. 338). They have been figured by Lea, Obs. 

 VII, 1860, PI. 29, fig. 102. As to the possible hermaphroditism of this species, see 

 Utterback (1916, p. 165). This question is yet rather obscure. Glochidia: 

 Lea (Obs. XIII, 1874, PI. 21, fig. 3); Surber (1915, fig. 3); Utterback (1916, p. 

 165). I have seen the glochidia of specimens from Arkansas. They are subovate, 

 higher than long, 0.18 X 0.20 mm. Surber gives: 0.17 X 0.20. In Utterback's 

 figures (0.175 X 0.100) apparently is a misprint. 



Breeding season: In Pennsylvania I found three gravid females with eggs 

 on Jime 17, 1909, which would indicate a very early beginning of the season. But 

 on the other hand I have females from Arkansas with fully developed glochidia 

 collected June 26, 1911, and May 19, 1911. A specimen from Indiana, collected 

 Aug. 9, 1912, had eggs. Surber's glochidia came from a specimen collected July 

 20, 1911. This is rather confusing, and additional data are much to be desired. 



Remarks: The chief characteristics of this species are the small size, rather 

 regular subelliptic outline, the inflated valves, dark epidermis, and beak-sculpture. 

 In Pennsylvania it apparently has been confounded with Eurynia fabalis, which 

 resembles it in its small size, but is more compressed, is more pointed behind, has 

 much heavier hinge teeth, and generally more or less distinct rays. 



Localities represented in the Carnegie Museum: 



Conneaut Outlet, Conneautlake, Crawford Co., Pennsylvania. 



Lake Erie, Put-in-Bay, Ottawa Co., Ohio (C. Goodrich). 



Crane Creek, and Ten Mile Creek, Ottawa Park, Lucas Co., Ohio (C. Goodrich). 



Grand Reservoir, Mercer Co., Ohio (C. Goodrich).'*' 



Tuscarawas River, Oliio (Holland collection). 



Scioto River and Ohio Canal, Columbus, Franklin Co., Ohio (Smith collection). 



Wabash River, Mercer Co., Ohio (C. Goodrich); New Harmony, Posey Co., Indiana (A. A. Hinkley). 



Big Creek, Solitude, Posey Co., Indiana (A. A. Hinkley). 



Hinkston Creek, Columbia, Boone Co., Missouri (D. K. Greger). 



Saline River, Benton, Saline Co., Arkansas (H. E. Wheeler). 



Ouachita River, Arkadelphia, Clark Co., and mouth of Cove Creek, Hot Springs Co., Arkansas (H. E. 



Wheeler). 

 Big Deceiper Creek, Gum Springs, Clark Co., Arkansas (H. E. Wheeler). 

 Malvern Creek, Malvern, Hot Springs Co., Arkansas (H. E. Wheeler). 

 Slough, Tulsa, Tulsa Co., Oklahoma (F. B. Isely). 



Distribution and Ecology (See fig. 27): Type locality, Fox River, Wisconsin 

 (Barnes). 



In Pennsylvania this species is known from but one locality, the outlet of 

 Conneaut Lake. Here I found it in small numbers at a point where a smaU run 



"8 This drains originally into the Maumee, but now into the Wabash at high water. 



