Amphipoda Synopidea. 13 



The pleopoda [PI. I, tig. 19]. The peduncles are elliptical, longer 

 than the Hagella; the number of articuli in the outer flagellum of the 

 first pair is 10, in the inner flagellum 9. The cilite of the flagella 

 are pedunculated, long, plumose; the peduncular part long, but shorter 

 than the rest [PI. I, fig. 20]. 



The unis [PI. I, fig. 21]. The first segment is only a little longer 

 than the second (5: 4); the last is nearly as long as the second. The 

 urus is as long as the first three pereional segments. The surface is 

 quite smooth. 



The first pair of uropoda. The peduncle is linear, reaching to the 

 posterior margin of the last ural segment. The rami are unequal, the 

 inner much the longest, both ending with a strong movable claw-like 

 spine. The outer ramus is shorter than the peduncle, finely serrated 

 along the inner margin. The inner ramus is longer than the peduncle, 

 the inner margin smooth, carrying only one short spine at the middle and 

 two very small at the lower corner, at the base of the great claw-like spine. 



The second pair. The peduncle does not reach to the posterior 

 margin of the last segment ; the rami are unequal in length, the inner the 

 longest, both ending with short, feebly curved spines, two in each. Both 

 rami are smooth on the outer margins and finely serrated along the inner. 



The third pair. The peduncle is very short, broader below; the 

 rami are unequal in length, the outer the longest. The outer ramus is 

 two-jointed, the terminal joint equals a third of the length of the basal 

 joint. The outer margins of both rami are smooth, the lower parts of 

 the inner margins carry four simple hairs in the outer ramus, three 

 in the inner one; at the lower end of the terminal joint of the outer ramus 

 there are two minute spines. The lower end of the inner ramus carries 

 also two minute spines and between them two long, strong hairs. 



The telson is very large, triangular, obliquely truncated behind, 

 divided beyond the middle by a longitudinal fissure. At the lower 

 ends there are some minute spines. The telson is longer than the 

 peduncle of the last pair of uropoda, almost as long as the last two 

 ural segments together. 



Colour. Ultramarine (Dana), hyaline. 



Length. 5 — 6 m.m. 



Hab. The tropical parts of the Atlantic. (S.M. U.M. CB.) 



