THE NAUTILUS. 55 



EURYNIA (MicROMYA) LiENOSA (Conrad). (See: Ortmann, 1912, 



p. 340). 



In addition to the specimens investigated previously (from 

 Mississippi), I received a gravid and discharging female from 

 H. E. Wheeler, collected May 19, 1911, in the Ouachita River, 

 Arkadelphia, and several gravid females collected in September, 

 1911, in Big Deceiper Creek, Gum Springs, Clark Co., Arkansas. 



The glochidia agree with those decribed previously, but their 

 general shape should be called subspatulate, with almost straight 

 anterior and posterior margins. Length, 0.20; Height, 0.27mm. 



EURYNIA (EURYNIA) SUBROSTRATA (Say). (See: Lampsilis s. 



Simpson, 1900, p. 546). 



Specimens from Big Deceiper Creek, Gum Springs, Clark Co., 

 Ark., collected by H. E. Wheeler, September, 1911. Two were 

 gravid females, one with eggs, the other with glochidia. 



Mantle connection between anal and supraanal long, over 

 twice as long as the short anal, and somewhat longer than the 

 supraanal. Inner edge of anal crenulated, that of branchial 

 with papillae. In the female, the inner edge of the mantle, 

 in front of the branchial, carries a row of numerous, small, but 

 distinct papillae, which are subcylindrical or subconical, of 

 rather uniform size (the largest in the posterior part), and are 

 somewhat distant from each other. A black streak extends 

 from the branchial to a certain distance forward. In the male, 

 the black streak is short, and the papillae are rudimentary and 

 very distant from each other. 



Palpi with one-third of the posterior margins connected. 

 Inner lamina of inner gills entirely connected with abdominal 

 sac, but sometimes a small hole is present at the posterior end 

 of the foot. 



Marsupium in the posterior half of the outer gills, in my 

 specimens, with 18 to 25 ovisacs. Edge with some blackish - 

 brown pigment. 



Glochidia subovate (not subspatulate), higher than long. 

 Length, 0.21; height, 0.26 mm. They are closely allied to 

 those of E. nasuta, but are distinctly smaller (0.25 X 0.29 mm. 

 in nasuta). 



