Descrihcd Species of Fresh Wafei- Cr/isfocea. 355 



3. B. VERNALis Verrill. Amer. Jour. Science, 2(1 ser., 

 xlviii, 25 (1809); Proc. A. A. A. S. for 1861), (S22.—Pachm1. 

 7th Rep. U. S. Geol. Survey (Hayden), 622 (1874); 12th Rep. 

 U. S. Geol. Survey (Hayden), ii, 342 {\m^).— Gisslev. Amer. 

 Nat. XV, 186 (18S1).— //r^y. Amer. Nat. xvi, 242 (1882). 



//a/>.— Massachusetts, Rhode Island, Connecticut, New York, Penn- 

 sylvania, Ohio, Indiana. 



IV. CHIROCE3PHALUS PrEYOST. 



1. (\ Hoi.MANi Ryder. Pruc. Phila. Acad. 1879, US.— Poch- 

 ard. 12th Rep. U. S. Geol. Survey (Hayden), ii, 351 (1888).— 

 Her rick. Bull. Scientific Lab. Denison Univ. i, 19 (1885). 

 Hah. — New York, Pennsylvania, Minnesota. 



V. STREPTOCEPHALUS BairI). 



1. S. Floridanus Packard. Amer. Nat. xiv, 58 (1880); 

 12th Rep. U. S. Geol. Survey (Hayden), ii, 350 (1888). 



jETaft.— Florida. 



2. S. Sealii Ryder. Proc. Phila. Acad. 1879, 200.— 

 Packard. 12th Rep. U. S. Geol. Survey (Hayden), ii, 348 

 (1883). 



Uab. — New York, New Jersey. 



3. S. Texanus Packard. Amer. Jour. Science, 3rd ser., ii, 

 111 (1871); 7th Rep. U.S. Geol. Survey (Hayden), 622 (1874); 

 12th Rep. U.S. Geol. Survey (Hayden), ii, 345 (1883). 



S. Watsoni Packard. liull. U. S. Geol. Survey (Hayden), 

 iii, 176 (1877). 



Hah. — Kansas, Texas. 



VI. THAMNOOEPHALUS PAf'KART). 



1. T. PLATYURUS Packard. Bull. U.S. Geol. Survey (Hay- 

 den), iii, 175 (1877); 12th Rep. U. S. G.-ol. Survey ( llayden), 

 ii, 353 (1883). 

 Ilab. — Kansas. 



