20 COLEOPTERA. 



Schaeffcr, Icon. Ins. pi. 134. jf. 5. a. b. 

 Schaeffer, Elcm. 1. 17. 

 Panzer, Faun. Ins. Germ. fuse. 3. No. 5. 

 Inhabits the still waters of Europe. 

 PI. 5. a. Natural size. b. The same magnified. 

 c. The head. d. A horn. e. A les;. 



