THE NAUTILUS. 65 



and occupies the posterior half (or more) of the outer gill, with 

 a small non-marsupial section at the posterior end. Ovisacs 10 

 to 17. 



Glochidia almost subspatulate, higher than long; 4, length 

 0.22, height 0.29. 



Color of soft parts whitish. Anal and branchial opening with 

 black pigment, and this black color runs forward along the 

 outer mantle edge in front of the branchial; on the inside of the 

 inner edge there is a reddish-brown streak, and also the papillae 

 are reddish-brown. The marsupium has a broad black edge. 



This species resembles much E. iris (Lea) in shell characters, 

 and also the anatomy and the glochidia are very similar. The 

 papillae of the mantle edge are not quite as large as those of E. 

 iris, and they are more variable in number and position. In 

 nebulosa the largest and most distinct papillae are in the anterior 

 part, where three or four sometimes stand a little closer together. 



The shell of some of my females is undistinguishable from U. 

 amoemis Lea (Simpson, p. 555), and I think that amoenus is an 

 additional synonym of nebulosus (Conrad). 



EuRYNiA (Micromya) vanuxemensis (Lea) (See:Ortmann, 1912 

 pp. 342). 



I collected a number of specimens on Sept. 17, 1912 in North 

 Fork Holston River, Saltville, Smyth Co., Va. Among them 

 were gravid females with glochidia. 



Mantle connection between anal and supraanal moderately 

 long, but shorter than the anal. And with distinct crenula- 

 tions. Branchial with papillae. 



Papillae in front of the branchial of the female as described 

 previously. The largest papillae are w'ell forward. In the 

 male, the papillae are represented by mere crenulations. Palpi 

 connected only at base of posterior margin. 



Inner lamina of inner gills entirely connected with abdominal 

 sac. Marsupium as described i)reviously, minimum number of 

 ovisacs 7, maximum 14. Edge of marsupium with brown or 

 black pigment. 



Shape of glochidia as figured (1. c. pi. 20, f. 6), but they 

 should be called subspatulate. Length: 0.23, height: 0.30 mm; 



