REPORT ON THE AMPHIPODA. 1573 



side-plates with the upper boundary not very distinct ; the first three segments of the 

 pleon large, with the postero-lateral angles not acute. 



Upper Antennae attached below near the front of the head ; the first joint of the 

 peduncle about as broad as long, the second very short, the third obscure or absent ; the 

 first joint of the flagellum large, strongly bent, the long convex margin surrounded by 

 a dense fringe of long filaments, the apex produced about to the end of the second 

 joint, with the margin facing that joint ciliated ; adjacent to the upper margin of the 

 joint there is a second brush of filaments and this margin has an elevated process at a 

 little distance from the apex ; the small second joint is longer than broad, with filaments 

 near and at the apex ; the third joint is much shorter and narrower, with filaments near 

 the apex and setules at it ; the fourth joint is as long as the two preceding together, at 

 first a little bulbous, then filiform, tipped with setules. In Claus' figure the apex of the 

 first joint of the flagellum is more strongly produced, the third joint is as long as the 

 second, and the fourth is linear, little longer than either of the preceding joints. 



Lower Antennae attached at the lower part of the back of the head ; the third (first 

 free) joint of the peduncle curved, rather elongate, thickest near the base ; the fourth 

 joint narrower, broken in our specimen. Claus says that the fourth joint reaches almost 

 to the pleon, and the following joint is equal to it in Claus' figure ; according to that 

 figure the first joint of the flagellum is nearly as long as the last of the peduncle, while 

 the second or terminal joint is extremely short. 



Upper Lip a small dome, rather wider than deep. 



Mandibles.- — The trunk very small, compared with the palp, the cutting edge with a 

 slightly produced tooth at the top, the remainder very finely denticulate, straight ; the 

 first joint of the palp longer and broader than either of the others ; the second a little 

 widened at the base, curved, shorter than the third ; the third more curved and narrower 

 than the second, apically pointed. Claus, in the character of the genus, states that the 

 first joint of the mandibular palp is only a little longer than the following joints, and in 

 fact figures the third joint of nearly equal length with the first. 



Maxillipeds. — The inner plate about as long as broad, not half the length of the 

 outer plates, which are rather broad at the base, the apices rounded, not meeting over the 

 inner plate, the margins smooth. 



First Gnathopods.— The first joint longer than all the rest together, with the hind 

 margin nearly straight, the front sinuous, the two ends of the joint being narrow, the 

 middle a little dilated; the second joint not broader than long, the third a little longer, 

 with one little setule on the hind margin ; the wrist a narrow oval, longer than the 

 hand, with a little setule and two hairs on the hind margin ; the hand narrow, with the 

 hind margin straight, armed below with three tiny setules, the front margin convex ; 

 the finger small, acute, less than a third of the lerjgth of the hand, with a minute setule 

 on the hind margin. 



