142 THE NAUTILUS. 



Soft parts very much like those of C. parra, but the black 

 spot behind the caruncle is not well marked, but represented 

 by a black streak, extending along the branchial opening for- 

 ward to the base of the caruncle, and beyond. Caruncle globu- 

 lar, subcylindrical, or pear-shaped, brownish or white, and 

 quite conspicuous upon a black base. In the male, the black 

 streak may be distinct or obscure, and the caruncle is entirely 

 missing. 



Rest of the anatomy as described previously; in one specimen, 

 however, the inner lamina of the inner gills was free for only 

 about one half of the length of the abdominal sac. In all spec- 

 imens, the supraanal was open. 



Glochidia identical with those of C. parva, Length: 0.18. 

 Height: 0.20 mm. 



Garunculina glans (Lea.) (see: Lampsilis (Carunndwa) glans 

 Simpson, 1900, p. 565). 



A sterile female from the Old River of Ouachita River, Arka- 

 delphia, Clark Co., Ark., collected by H. E. Wheeler, July 17, 

 1911. 



Inner edge of mantle, from branchial to caruncle, and a little 

 in front of the latter, with a black streak, this streak, most in- 

 tense just behind the caruncle, forming an ill-defined black 

 blotch. Caruncle subcylindrical, brown. 



Edge of sterile marsupium dark brown (no dark pigment 

 seen here in C. parva and texasensis") . 



MEDION T IDUS CONRADICUS (Lea). (See Ortmann, 1912, p. 335.) 



Only one male and a gravid female were at hand when I de- 

 scribed the anatomy of this form. Recently I have collected a 

 large number in North Fork, Holston River, Saltville, Smyth 

 Co., Va. (September 17, 1912), and in Clinch River, Richland 

 and Raven, Tazewell Co., Va. (September 20 and 21, 1912), 

 and preserved the soft parts of six males, two sterile, and six 

 gravid females. All of the latter have glochidia, but in some 

 they are immature, thus indicating the beginning of the breed- 

 ing season early in September. 



Soft parts as described, and inner lamina of inner gills always 

 free, except at anterior end. Marsupium as described, but 



