158 CARL B0VALL1US, AMPHIPODA HYPERIIDEA. I. 2. HYPERIID^E. 



Hyperia medusarum. 



minal joints is to be seen. In very young females the flagellum is thicker, and a little 

 tumid. 



The second pair of antennae are shorter than the first pair, but reach farther 

 downwards. The first visible joint of the peduncle is broader than long, the glandular 

 cone is distinct; the second joint is as long as the first; the third is scarcely shorter 

 but much narrower. The flagellum is one-jointed, conical and much narrower than 

 that of the first pair; it is equal in length to the whole peduncle; at the apex there are 

 some few minute hairs. 



The mandibles (PI. IX, fig. 17) are exactly like those in the male, but a little 

 more robust. The last joint of the palp 1 ) is somewhat broader and more densely provided 

 with hairs. 



The peroeon has the first segment somewhat shorter than the second, and the second, 

 third and fourth segments are a little longer comparatively than in the male. 



The epimerals are somewhat deeper than in the male, but in other respects like. 



The ovitectrices are elongate-ovate, a little broader below; they are longer than the 

 branchial sacks. 



The first and second pairs of perceopoda are exactly like those pairs in the male. 



The third and fourth pairs are like those in the male, but the glands are often 

 more strongly developed and the dactylus is sometimes transformed into a spout-like 

 instrument, no doubt in order to procure an easier transmission of the secretion from the 

 glands (PI. IX, fig. 18). 



The fifth, sixth and seventh pairs are shorter than the third and fourth and some- 

 what thicker than in the male. The dactylus of one or another of these pairs is often 

 transformed in the same manner as in the third and fourth pairs (PI. IX. fig. 19). 



The pleon is less powerful than in the male, and somewhat shorter than the last 

 four pergonal segments together. 



The pleopoda are a little shorter comparatively than in the male. 



The urus is exactly as long as the last pleonal segment. 



The uropoda and the telson are like those organs in the male. 



The young just hatched. 



PI. IX, fig. 20 and 21. 



The head is deep and broad but scarcely longer than the first pereeonal segment. 



The percvon shows seven distinct segments, the sixth longest. 



The epimerals form small extant tubercles. 



The peroeopoda (PL IX, fig. 21) of the first and five following pairs are equal in 

 length, composed of five joints each; the first joint is the longest, the following are equal 

 in length, and as broad as long; the dactylus is very long, and curved. The seventh 



J ) I give a drawing of the mandibles of the female of this species, the type for the genus, because Claus 

 in his »Platysceliden», p. 3, suggests that the females of all the Hyperids, like the females of Oxycephalida, 

 and its nearest relatives should want a mandibular palp. 



