94l> THE VOYAGE OF H.M.S. CHALLENGER. 



Lower Antennse. — Peduncle longer than that of the upper antennas ; the first three 

 joints very short, the gland-cone well developed, the third joint carrying several setae 

 on its lower margin ; the fourth joint long, shorter than the second of the upper 

 antennas, which it resembles in shape ; the lower margin armed with slender spines ; 

 the fifth joint straight and thin, a little shorter than the fourth, armed with slender 

 spines, of which many are elongate ; the flagellum of eleven slender joints, armed with 

 slender spines, together shorter than the peduncle. 



Upper Lip broadly and smoothly rounded, delicately ciliated. 



Mandibles. — Cutting plate with the edge divided into six teeth, the outermost the 

 largest ; secondary plate on the left mandible similar to the principal, but smaller ; on 

 the right mandible this plate is slighter, and ends in two prominent teeth, which curve 

 the one towards the other, the outer being the longer, and having two or three denticles 

 on its side ; the spine-row of three plumose spines on the left, and two on the right 

 mandible; the molar tubercle large and strong, the crown of irregular shape, set with 

 very many small denticles, and carrying at one corner a short plumose seta ; it 

 has on the forward margin a small protuberance ; there is an articulating process, 

 but no palp. 



First Maxillse. — Inner plate small, oval, with two plumose setae on the inner 

 margin, the lax-ger close to the apex ; the outer plate broad, with nine spines on the 

 truncate distal margin, several of them long and denticulate, three short, denticulate on 

 both edges near the apex ; the palp reaching a little beyond the outer plate, the first 

 joint short, the second long, with six slender spines on the oblicpie distal margin, and 

 one some way from the apex on the outer margin. 



Second Maxillse. — Inner plate narrower than the outer, carrying eleven plumose 

 spines, seven on the distal, four on the inner margin ; the outer plate with about 

 sixteen spines round the distal margin, the outermost a small one. 



Maxillipeds. — Inner plates short, not reaching so far as the distal end of the first 

 joint of the palp, carrying five long plumose spines on the squared distal margin, two 

 or three on the inner margin, and some transverse rows on the outer surface, in one 

 of which two of the spines exceed all the others in stoutness ; the outer plates very 

 long, reaching beyond the middle of the third joint of the palp, the slightly concave 

 inner margin armed with eighteen or nineteen small sharp spine-teeth, and the apex 

 with one rather larger than the rest ; first joint of the palp short, the second con- 

 siderably longer, broad, armed on the inner margin, and the outer surface near it, with 

 numerous groups of long slender spines ; the third joint longer than the first, beset 

 with numerous groups of spines ; the finger very short, the sharp nail accompanied by 

 a cilium. 



First Gaathopods. — Side-plates short, sharply angled below in front, the point 

 projected forwards. The first joint, as in all the legs, reaching much beyond the side- 



