GAMMARIDEAN AMPHIPODA 



145 



Figure 31. — Eurystheus spinosus Shoemaker, male, 2.8 mm., station 38-A-2: a, pereopod 

 1 ; b, pereopod 3, minus coxa; c, right gnathopod 2, medial view; d, left gnathopod 2, lateral 

 view; e, ventrodistal end of outer ramus of uropod 1;/, g, h, uropods 1, 2, 3; i, head and 

 epistome-upper lip complex; j, enlarged view of posterior edge of pleonal epimeron 3. 



and sharpness. The gnathopods of some young individuals of M. 

 martesia are like those of E. spinosus and some of the former specimens 

 may have been misidentified because of this similarity. The third 

 uropods of M. martesia appear to have longer, more slender rami than 

 those of E. spinosus, but without dissecting and mounting the uropods 

 in precisely replicated planes this characteristic is not useful for 

 identification. Because the writer is not satisfied with the identifica- 

 tions of all specimens in both species he has not removed the uropods 

 in anticipation that further study of large suites of adults of the two 

 species will reveal other, more reliable characters. 



There is no evidence that M. martesia is the terminal adult of E. 

 spinosus. Transformation of male gnathopod 2 from one condition 

 to the other would be of extraordinary degree but this situation must 



