156 CAEL BOVALLIUS, AMPHIPODA HYPER1IDEA. I. 2. HYPERlIDiE. 



Hyperia medusarum. 



lower hind corner there are four long bristles. The tibia is much longer than the genu; 

 the lower hind part is more produced than in the first pair; the under margin fringed 

 with about ten long bristles. The carpus is somewhat shorter than the two preceding 

 joints together, dilated, and a little produced, covered with long bristles; the front margin 

 is convex, slightly notched; the hind margin is nearly straight; the front side of the carpal 

 process is spoon-shaped, much shorter than a third of the hind margin of the metacarpus; 

 the margins are fringed with very long bristles. The metacarpus and the dactylus 

 are exactly similar to those joints in the first pair. Glands as in the first pair. 



The third and fourth pairs (PI. IX, fig. 12) are robust, with thick joints. The 

 femur is ovate; the hind margin is smooth, armed at the lower corner with two long 

 bristles and a third one a little above. The genu is as long as broad, the hind corner being- 

 set with three bristles. The tibia is much longer than the genu, the hind margin with 

 four to five long bristles. The carpus is only a little longer than the tibia (5: 4); the 

 hind margin is straight, not serrated, set with six long bristles; these bristles are almost 

 as long as the breadth of the joint. The metacarpus is somewhat longer than the carpus 

 (6: 5) and more slender; the hind margin is nearly straight, not serrated, armed with 

 six or eight long bristles. The dactylus is robust, almost straight, shorter than a third 

 of the metacarpus. Glands are especially well developed in the femur. 



The fifth, sixth and seventh pairs (PI. IX, fig. 13) are a little shorter than the two 

 preceding and robust, with thick joints. The femur is oblong, not much dilated; the 

 front margin is slightly convex, smooth; the hind margin is almost straight. The genu 

 is somewhat broader than long, and smooth. The tibia is considerably longer than the 

 genu, very thick and broad, and smooth. The carpus is as long as the tibia, and more 

 slender; the front margin is straight, not serrated, without bristles. The metacarpus 

 is a little longer than the tibia (5: 6), and half as long as the femur, but shorter than 

 the metacarpus of the third and fourth pairs; the front margin is not serrated, and without 

 bristles. The dactylus is thick and stout, slightly curved, and about equal in length 

 to a fourth of the metacarpus; at the base it shows a large oblong opening, the outlet 

 for the glands which are present in all the joints. 



The pleon equals in length the last five peraeonal segments together. The lateral 

 parts of the last two pleonal segments are straight below; the hind corner is angular. 

 The lateral part of the first segment is obtusely rounded below. 



The pleopoda (PI. IX, fig. 14) are comparatively slender. The peduncle is oblong, 

 with nearly flat sides; it is scarcely longer than the rami. The coupling spines 

 (PI. IX, fig. 15) are hook-shaped, with two spine-like teeth below the hooked apex. The 

 cleft bristle is slender, not very stout; the basal portion densely fringed with long hairs. 

 The outer ramus of the first pair has seventeen joints, the inner fifteen. 



The urus is a little longer than the last ural segment; the first ural segment is 

 somewhat longer than the last coalesced one; this latter is almost twice as broad as long, 

 with the hind corners rounded. 



The uropoda (PL IX, fig. 16). The first pair reach almost to the apex of the last 

 pair; the peduncle is linear, three times as long as broad, and a little longer than the 

 inner ramus; the outer ramus is narrow, elongate, scarcely shorter than the inner; 



