ISOPODS OF NORTH AMERICA. 



411 



</. Propodus of first pair of legs armed with two processes, one triangular and the 

 other truncate. Second pair of antenna? shorter than the body. Inner 

 branch of uropoda twice as long as outer branch. 



Mancasellus danielsi Richardson 



MANCASELLUS BRACHYURUS Harger. 



Mancasellus brachyurus HARGER, Am. Jour. Sci. and Arts, (3), XI, 1876, pp. 304- 

 305. UNDERWOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 359. BOVAL- 

 uus, Bihang till K. svenska Vet.-Akad. Handl., XI, No. 15, 1886, p. 39. 

 RICHARDSON, American Naturalist, XXXIV, 1900, p. 296; Proc. U. S. Nat. 

 Mus., XXIII, 1901, p. 551. 



Localities. McKee's spring, Lexington, Virginia; Gaylord, 

 Virginia. 

 Reported injurious to water cress. 



FIG. 460. MANCASELLUS BRACHYURXJS. a, ABDOMEN WITH UROPODA. x 9}. b, SECOND PLEOPOD OF 



HALE. X 27}. C, FIRST PLEOPOD OF FEMALE. X 27}. d, THIRD PLEOPOD OF MALE. X 15}. , UROPOD. 



x 27}. /, FIRST LEG. x 27}. g, THIRD PLEOPOD OF FEMALE, x 15}.' h, FIRST PLEOPOD OF MALE. 

 X27}. 



Body. about two and a third times longer than wide, 6 mm. : 14 mm. 



Head a little more than twice as wide as long, 1 mm. : 3 mm. , with 

 the anterior margin slightly excavate between the antero-lateral angles. 

 The sides of the head are entire. The eyes are small, round, com- 



