136 THE NAUTILUS. 
Anodonta gracilis Lea. Ohio R., Beaver, 9; Coraopolis, 9. 
Anodonta marginata Say. Ohio R, Coraopolis, 4; Beaver R., 
Wampum, 100. 
Margaritana rugosa Bar. Ohio R., Coraopolis, 5; Beaver, 1; Bea- 
ver R., Wampum, 6. 
Unio aesopus Green. Ohio R., Coraopolis, 3; Beaver R.. Wam- 
pum, l. 
Unio alatus Say. Ohio R., Coraopolis, 14; Beaver, 1. 
Unio coccineus (Hild) Lea. Beaver R., Wampum, 7. 
Unio cooperianus Lea. Ohio R., Beaver, 1; Corapolis, 4. 
Unio cornutus Bar. Ohio R., Beaver, lL; Corapolis, 1. 
Unio cylindricus Say. Ohio R., Corapolis, 1; Beaver, 1; Beaver, 
R., Wampum, 2. 
Unio crassidens Lam. Ohio R., Coraopolis, 40; Beaver, 3. 
Unio donaciformis Lea. Ohio R., Coraopolis, 2. The larger speci- 
men is 66 mm. long. 
Unio elegans Lea. Ohio K., Coraopolis, 3. These specimens out- 
wardly appear like rubiainosus from the same locality, in this respect 
being much more elongated and less sharply carinated than the typical 
elegans. 
Unio gibbosus Bar. Ohio K., Coraopolis, 41; Beaver, 9; Beaver 
R., Wampum, 28. 
Unio irroratus Lea. Ohio R., Beaver, 1. 
Unio kirtlandianus Lea. Beaver R., Wampum, 150. 
Unio lens Lea. Ohio R., Coraopolis, 3; Beaver R., Wampum, 25. 
Unio ligamentinus Lam. Ohio R., Coraopolis, 100*; Beaver, 20; 
Beaver R., Wampum, 70. In the Ohio this was the most abundant 
mollusk, exceeding in numbers all the other Unios put together. 
Unio luteolus Lam. Ohio R., Coraopolis, 16; Beaver R., Wampum, 
18. 
Unio metanever Raf. Ohio R., Coraopolis, 12; Beaver, 5. 
Unio multiradiatus Lea. Beaver R., Wampum, 14. 
Unio obliquus Lam. (U. subrotundus and varicosus Lea.) Ohio 
R., Coraopolis, $1; Beaver, 8. Forty adult specimens of the ob/iquus 
type presents so many gradations corresponding on either hand to sub- 
rotundus and varicosus in the series at the Academy of Natural 
Sciences named and presented by Isaac Lea, that I am obliged to lump 
them as above. There is also a complication regarding the appli- 
cability of the name mytiloides Raf., to some of these. It is probable 
