AND EMBRYONIC FORMS. » 405 



Remarks. — These specimens were sent by Bishop Elliott, from Tobesaufkie Creek, 

 below Macon, Georgia. They were from five to six inches wide by three to four 

 inches long. 



Unio angustatus, Lea. Trans. Amer. Phil. Soc, vol. iv. pi. 17, fig. 43. Obs. vol. i. pi. 124. 



Branchial uterus occupies the whole length of the outer branchiae, like nasulus. 

 Branchice wide, slightly curved below, the inner ones the larger, free nearly half the 

 length of the abdominal sack. Palpi large, thin, curved below and rounded at the end, 

 united half way down the posterior edges. Mantle very thin, with a broad thickened 

 margin. Branchial opening rather large, with small brown papilla? on the inner edges. 

 Anal opening rather large, with very small brown papillce on the inner edges. Super- 

 anal opening large, united for a short distance below. Color of the mass light salmon. 



Prom Tobesaufkie Creek, Georgia, Bishop Elliott. 



Unio decisus, Lea. Trans. Amer. Phil. Soc, vol. iv. pi. 12, fig. 23. Obs. vol. i. p. 102. 



Branchial uterus occupies the whole length of the outer leaves of the branchise. Ova 

 not matured enough to show the embryonic form. Branchiae rather large, rounded 

 below, inner ones much the longer, free more than half the length of abdominal sack. 

 Palpi small, ovate, united above or a short distance on the posterior edges. Mantle 

 very thin, slightly thickened on the edges. Branchial opening small, with very small 

 papillae. Anal opening very small, with very minute papilla?. Super-anal opening 

 rather large, colored within and united below for a short distance. Color of the mass 

 whitish. 



Othcalooga Creek, Georgia, Bishop Elliott; and Columbus, Mississippi, Dr. 

 Spillman. 



Unio glans, Lea. Trans. Amer. Phil. Soc, vol. iv. pi. 8, fig. 12. Obs. vol. ii. p. 92. 



Branchial uterus occupies the posterior of the outer branchise, like heterodon, having 

 a few large ovisacks. Branchial rather small, rounded below, the inner ones rather 

 the larger, free for a short distance. Palpi small, subtriangular, not united on the 

 posterior edges. Mantle thin, with a broad thick margin. Branchial opening large, 

 with numerous brown papillae on the inner edges. Anal opening small, with small 

 brown papilla? on the inner edges. Super-anal opening rather small, not united 

 below on the edges. 



Embryonic shell pouch-shape, very near to that of parvus, which is near to rectus, 

 but it is more rounded. It has no hooks. 



Remarks. — On the inner edges of both sides there is a caruncle immediately below 

 the branchial opening, similar to that described in jxtrvus and paulus. 



Othcalooga Creek, Georgia, by Bishop Elliott. 



103 



