EEPORT ON THE AMPHIPODA, 817 



with few apical setse, those of the outer plate the longer, those of the inner extending 

 more down the inner margin. 



Maxillipeds. — Inner plates not reaching much beyond the base of the first joint of 

 the palp, Avith two spines on the apical, and one on the inner margin ; outer plates 

 narrow, not reaching the end of the first joint of the palp, the inner margin carrying two 

 small setse and three s^^ine-teeth, the largest of these being apical ; the first joint of the 

 palp subequal in length to the third, the second joint longer than either, with seven or 

 eight setse on or near tlie inner mai'gin ; the third joint with about the same number of 

 setse distributed over it ; the fourth joint as long as the third, finger-formed, but with the 

 inner margin not concave ; the dorsal cilium short, the nail short and sharp, spine-like, 

 with a couple of cilia near it on the inner margin. 



First Gnatliopods. — Side-plates expanded below, the hinder part of the lower margin 

 carrying five setas and a cilium, another cihum also in advance of the setse. The first 

 joint not reaching below the side-plate, carrying five setse, four of them very long, on the 

 hind margin ; second joint as long as the thuxl ; the third rather broader above than 

 below, with a small process filling up the narrow space in front between the second and 

 fourth joints ; the wrist not quite so long as the second and third joints together, broader 

 above than below, with a group of setse at the top of its free hind margin, its lower apex 

 attached to the front margin of the hand, which seems partially to rest on its free hind 

 margin ; the hand oblong, broad, muscular, the front margin longer than the hinder, 

 which is outdrawn into a small tooth-process ; on this is seated a strong spine, not 

 reached by the tip of the finger when closed over the convex, ciliated palm ; there are 

 two cilia on the hind margin, one on the apex in front ; a short dorsal cilium on the 

 finger. 



Second Gnatliopods. — Side-plates oblong, distally less broad than those of the first 

 segment, similarly armed. The branchial vesicle narrow, nearly as long as the first joint 

 of the limb ; the marsupial plates in the female narrower than the branchise, of the same 

 length, with a few long setse on the front margin. The joints of the limb similar to those 

 of the fii'st gnathopods, but larger, the third joint longer than the second and as long as 

 the wrist, with which it forms a small cup for the broad, muscular, oblong hand, which in 

 both sexes greatly exceeds the size of the hand of the first pair, the palm margin being 

 also more oblique, and its tooth process stronger. 



First Perieopods. — Side-jjlates like those of the preceding segment. Branchial 

 vesicles oval, longer and broader than the first joint of the limb. First joint reaching 

 fully as far down as the side-plate, with setse on the convex hind margin ; third joint 

 subequal in length to the fourth and fifth together, with setse on the hind margin; fourth 

 joint rather shorter than the fifth, narrower than the third, oval, with setse and spines 

 on the hind margin, an apical spine longer than the fifth joint ; the fifth joint narrow, 

 with one seta at the centre, and a group of spines and setse at the apex, of the hind 



(ZOOL. CHALL. EXP. — PART LXVII. 1887.) Xxx 103 



