410 UNIONID2E, THEIR SOFT PARTS 



TInk) fraternus, Lea. Trans. Amcr. Phil. Soc, vol. x. pi. 16, fig. 15. Obs. vol. v. p. 19. 



Branchial uterus . No ova were found here, but small, imperfect ones were 



found in abundance in the ovarium. Branchial large, much curved below, inner 

 ones very much the larger, free nearly the whole length of abdominal sack. Palpi 

 small, subtriangular, not united on the posterior edges. Mantle very thin, with a 

 very large mai'gin. Branchial opening rather large, with small, dark-brown papillae. 

 Anal opening very large, with numerous very minute, dark-brown papillae. Suiter- 

 anal opening very small, not united below. Color of the mass whitish. 



Flint River, near Albany, Georgia, Bishop Elliott. 



IJnio ckassidens, Lam. An. sans Vert., vol. vi. p. 71. 



Branchial uterus . No ova were found here, but the ovarium was filled. 



Branchial very large, rounded below, angular posteriorly, inner ones much the 

 larger, free nearly two-thirds the length of the abdominal sack. Palpi small, round 

 below, not united on the posterior edges. Mantle thin, with a very broad margin. 

 Branchial opening rather large, with small, brownish papilla?. Anal opening very 

 large, with numerous small, brownish papillae. Super-anal opening rather small, 

 slightly attached below. Color of the mass whitish. 



Etowah River, Cass County, Georgia, Bishop Elliott. Common in the Ohio 

 Basin. 



Unio Conradiantjs, Lea. Trans. Amer. Phil. Soc, vol. v. pi. 9, fig. 23. Obs. vol. 1, p. 175. 



Branchial uterus . No ova were found here, but the ovarium was filled. 



Branchial rather large, inner ones extending much anteriorly, free nearly half of the 

 abdominal sack. Palpi small, suboval, not united on the posterior edges. Mantle 

 thin, black on the posterior margin to the middle of the base. Branchial opening small, 

 with small, brown papillae. Anal opening large, with very small, brown papilla?. 

 Super-anal opening rather small, not united below. Color of the mass whitish. 



Etowah River, Georgia, Bishop Elliott. 



Remarks. — In one of the three specimens before me, I found a filamentous byssus. 

 The other two had the cicatrix where it was once united. The cicatrix is attached to 

 the central part of the basal edge of the foot, in a longitudinal impression or cut. 

 Posterior and close to this filament are the rudiments of a second one, which may, 

 perhaps, be the remains of one severed close to the cut. The filament which 

 remains is nearly one-fourth of an inch long, and is evidently broken off, so that it is 

 impossible to say with certainty what was its original length when attached to the 

 foreign substance to which it adhered. In this specimen the byssus is not thicker than 

 a human hair, but in a specimen of acutissimus it was an inch long, and much thicker 

 and flatter. 



