AND EMBRYONIC FORMS. 445 



found in the ovarium as well as in the branchial uterus. Branchial large, inner ones 

 much the larger, rounded below, free nearly the whole length of the abdominal sack. 

 Palpi rather lai-ge, subtriangular, united a short distance on the j>osterior edges. 

 Mantle very thin, thickened on the margin. Branchial opening rather large, with 

 numerous small, dark brown papillae. Anal opening large, with numerous small, 

 dark brown papilla. Super-anal opening large, slightly united below. Color of the 

 mass light salmon. 



Abbeville, South Carolina, Prof. Tuomey, and Macon, Georgia, J. C. Plant, Esq. 



RemarJcs — This species belongs to the group of which complanatus may be con- 

 sidered the type. The branchial uterus in all respects resembles that species. 

 There were no ova sufficiently developed to give the embryonic form of the shell. 



Unio Abbevillensis, Lea, Jour. Acad. Nat. Sci. (2), vol. iv. p. 51, and Obs. vol. vi. p. 51. 



Branchial uterus . Branchice rather large, inner ones the larger, much 



rounded below, free nearly the whole length of the abdominal sack. Palpi small, 

 subtriangular, united only at the upper posterior edges. Mantle thin, thickened at 

 the margin. Branchial opening rather small, with numerous small, brown papilla?. 

 Anal opening small, with numerous small, brown papilke. Super-anal opening rather 

 large, slightly united below. Color of the mass light salmon. 



Abbeville, South Carolina, Prof. Tuomey, and Macon, Georgia, J. C. Plant, Esq. 



Remarks. — A single specimen only, a male, was received from Mr. Plant, with the 

 soft parts. This species belongs to the complanatus group. 



Unio EmmonSii, Lea. Jour. Acad. Nat. Sci. (2), vol. v. p. 56, and Obs. vol. viii. p. 60. 



Branchial uterus occupies the whole length of the outer branchice. Ova were 

 found in the ovarium as well as in the branchial uterus. Branchial very long and 

 narrow, inner one posteriorly the larger, united more than half the length of the 

 abdominal sack. Palpi small, ovately transverse, united only at the upper posterior 

 edges. Mantle very thin, thicker on the margin. Branchial opening rather large, 

 with small brown papillae. Anal opening very small, with very small, brown papillce. 

 Super-anal opening rather small, united below for a long distance. Color of the mass 

 very light salmon. 



Roanoke River, at Weldon, N. C, Prof Emmons ; and Macon, Geo., J.C. Plant, Esq. 



Remarks. — This species belongs to the nasutus group. Two specimens were re- 

 ceived in alcohol from Mr. Plant, a male and female. In the soft parts this species 

 differs but little from nasutus. 



113 



