254 CARL BOVALLIUS, AMPHIPODA HYPERIIDEA. I. 2. HYPEKIIDuE. 



Parathemisto oblivia. 



and tapers towards the apex; the inner (= hind) margin is almost straight and serrated, and has 

 a few stout, spine-like bristles, the outer (= front) margin is convex, and armed with slender 

 bristles; the claw is a little curved, and somewhat shorter than the hand (= metacarpus).» 



»The third joint of the second pair is produced at the lower hiad corner, and has some 

 bristles; the fourth joint, or carpus, is longer, and is strongly produced at the lower hind corner 

 into a narrow heel, which at the apex and on the inner (= front) margin has almost spine-like 

 bristles. The hand (= metacarpus) is about as long as the carpus, triangulär, with the inner 

 (= hind) margin serrated and provided with a few stout bristles; the outer (= front) margin is 

 frino;ed with slender bristles.» 



The m al e. 



Pl. XII, tig. 11—16. 



The body is feebly carinated dorsally, but the hind corners in the median line of 

 the perteonal and pleonal segments are not produced into angular processes as for instance 

 they are in Eutheviisto coiwpressa. 



The head is nearly twice as deep as long, and is miich deeper than the perjeon. 

 The antennal groove commences at the middle of the front side, so that the first pair of 

 antennge are inserted a little below the middle of the head. 



The fi^rst pair of antenna; (Pl. XII, fig. 11) are shorter tlian the second, and rcach 

 beyond the hind margin of the last peraeonal segment. The first joint of the peduncle 

 is quite as long as the two following together. The first joint of the flagelluin is long, 

 conical, with feebly bulging sides, and is nearly twice as long as the whole peduncle, 

 the second and third flagellar joints are very short, the fourth is as long as the two 

 preceding together, the fifth and following are long, slender, cylindrical, and increase slowly 

 in length towards the last joint. The flagellar joints are fifteen in nuinber. 



The second pair of antennte reach to the hind margin of the second pleonal seg- 

 ment. The first free joint of the peduncle is as long as broad, and somewhat shorter 

 than the second; the third joint is considerably longer than the second, and is more slender. 

 The first flagellar joint is longer than the last peduncular joint, the following are sub- 

 equal in length, slender, cylindrical, and considerably shorter than the first. They are 

 fifteen in number. 



The mouth- organs closely resemble those in Parathemisto jaj^onica, which are de- 

 scribed below (p. 259 and 260). 



The perceon has the first four perasonal segments about equal in length; the sixth 

 is the longest of all. 



The epimerals are somewhat longer than the under margins of the corresponding 

 segments, overlapping each other with the broadly rounded anterior or posterior end. 



The branchial säcks are attached to tJie second and four following pairs of peraio- 

 poda; the are shorter and thicker than those in the genus Hyperia. 



The first pair of perceopoda (Pl. XII, fig. 12) are a little shorter and less robust 

 than the second. The femur is narrow^ almost linear, and a little curved, the front 

 margin being feebly concave, with a long narrow groove or furrow for the reception of 



