FRESH- WA TEE A MPHIPODA — 1 1 ECKEL. 



45 



GAMMARUS PURPURASCENS W. P. Hay. 



Gammarus purpurascens W. P. Hay, Proc. U. S. Nat. Mus., XXY, 1902, p. 433. 



Eyes large, reniform; larger than in Gammarus liw.nseim Smith, 

 which species Gammarus jyia'puraxcens resembles. First antenna 

 longer than in Gammarus llmnseus^ about half the length of the bod}'; 

 first and second segments of the peduncle nearly equal in length; third 

 segment about half as long as the second; flagelkim composed of 

 twenty-five to thirt}' segments; secondary fiagellum consisting of fou»" 



Fig. 10.— Gammakus purpurascexs, male. Nickajack Cave. ah. d., dorsal side of the termi- 

 nal SEGMENTS OF THE ABDO.MEN. 



segments, the distal one ver}' short and tapering. Second antennoe 

 slightly more than half as long as the first pair; peduncle exceeding 

 that of the first pair in length, the two distal segments elongated, 

 nearly equal; fiagellum slightly shorter than the peduncle, composed 

 of about ten segments, each of which bears a small olfactory club. 



First gnathopods of the male with the carpus ])roadh' triangular, 

 nearly as broad as the propodus; propodus broad, narrowed distall}^; 



