292 



CARL BOVALLIUS, AMPHIPODA HYPEK1IDEA. I. 2. 



HYI'EKIIDtE. 



Euthemisto libellula. 



The second pair of antenna?. (PI. XIII, fig. 5) are longer than the first pair; the 

 third peduncular joint is fully as long as the two preceding together. The single flagellar 

 joint is straight, slender, and tapers feebly towards the apex; it is twice as long as the 

 whole peduncle, and is fringed with short hairs on the under margin. In the young fe- 

 male the flagellar joint is scarcely longer than the peduncle. 



The mouth-organs are exactly like those in the male. 



The dorsal line of the peroeon is very convex; the fifth segment is the longest. 



The epimeral of the fifth pair of perseopoda is the longest, while the preceding de- 

 crease anteriorly in length and the following posteriorly. 



The branchial sacks (PI. XIII fig. 22) are about half as long as the femora of the 

 corresponding pairs of perreopoda, and are broad, almost truncated at the apex. 



The ovitectrices (PI. XIII fig. 22) are elongate-ovate, narrow at the apex, and are 

 considerably longer than the branchial sacks. 



The perwopoda (p. 291, fig. 2 and 3) are closely similar to those in the male; in the 

 young female the carpal process of the second pair does not reach to the apex of the metacar- 

 pus, but is still much more than half as long as the hind margin of the metacarpus; also the 

 tibial process in this pair, and in the fifth pair, is less produced than in the adult animal, 

 though more produced than, for instance, in the adult animal of Euthemisto compressa. 

 Sometimes the dactylus, and even the metacarpus, of the sixth and seventh pairs is trans- 

 formed for giving outlet to the glandular secretion. 



The pleon is not fully as long as the last five pergonal segments together, and is 

 distinctly carinated; the hind corner of the segments is sharp-pointed, but not produced. 



The urus is a little longer than the last pleonal segment in the adult female, in 

 the young it is somewhat shorter. 



The uropoda (p. 291, fig. 4) are like those in the male. 



Euthemisto libellula, Mandt. Young female. 

 Copy from C. Bovalhus, Arct. and Antarct. Hyper., pi. 47, fig. 104, 107, and 108. 



Fig. 1. The animal from the side. 2. The first pair of peneopoda. 3. The second pair. 



