THE NAUTILUS. 65 



The sculpture has mostly been eroded, but in parts the sculp- 

 ture remains, resembling that of other members of the genus. 



Bathytoma clarkiana if restored, would measure 116 mm, over 

 all, the body whorl measuring 68 mm, the spire 48 mm. 



The photos submitted to you have also been sent to the 

 scrutiny of Dr. R. H. Tremper of Ontario, and his reply reads 

 thus; "The photo is very interesting. I suspect your shell 

 represents some extinct form of Bathytoma. I have not seen a 

 specimen of this genus so long, nor so attenuate. Your fossil 

 is not B. tremperiana of Ball. The latter is a very different 

 shell and very much smaller, good-sized specimens measuring 

 67 mm. ; body whorl 82 mm., spire 35 mm., making the body 

 whorl shorter than the spire, while in your specimen the body 

 whorl measures 68 mm., and the spire 48 (if restored)." 



STUDIES IN NAJADES. 



BY A. E. ORTMANN. 



(Continued from page 47.} 



ALASMIDONTA (PEGIAS) FABULA (Lea) (See: Pegias f. Simp- 

 son, 1900, p. 661). 



Three males and two gravid females (with gjlochidia) 

 from North Fork Holstoii River, Saltville, Smyth Co., Va., 

 collected Sept. 17, 1912. 



Anal opening separated from the supraanal by a well de- 

 veloped, but rather short mantle-connection. Inner edge of 

 anal crenulated, that of branchial with papillae. Posterior 

 margins of palpi connected for about one third of their length. 



Inner lamina of inner gills free in about the posterior half 

 of the length of the abdominal sac, or a little more, so that 

 the connection in front is distinctly longer than usual. Gills 

 of Anodontine structure, in the female only the outer ones 

 are marsupial, have lateral water canals, and are distended 

 at the edge. The glochidia fill the ovisacs in a mass, which 



