1540 THE VOYAGE OF H.M.S. CHALLENGER. 



on the outer edge ; the fifth joint similar, of nearly equal length, narrower, with only 

 one cilium on the outer edge near the distal end ; the first joint of the flagellum abruptly 

 narrower than the last of the peduncle and considerably longer ; the second joint still 

 more slender, folded closely back against the first and perhaps nearly half its length ; the 

 two joints of the flagellum are so delicate and so closely fitted into a groove of the head 

 that it is very difficult to draw them out without breaking them. 



Epistome conical ; Upper Lip shallow, bilobed. 



Mandibles with a narrow trunk bent about at a right angle in front, the cutting- 

 edge having a sharp produced tooth at the top and a sinuous front margin, part of which 

 is very finely denticulate ; the secondary plate on the left mandible a little widened 

 distally with its front edge finely denticulate ; the bent front portion of the mandibles 

 presents a fold or thickening of the inner surface, with a spine-like projection at the 

 rear end ; the three-jointed palp is large, placed well forward on the top of the angle 

 of the trunk, the first joint rather longer than the following two together, and except 

 at the extremities much broader ; the second joint narrowly oval, a little wider, but 

 rather shorter than the apically acute third joint ; these two joints are very easily 

 detached from the first. 



First Maxillae. — A narrow rectangular lamina much longer than broad, apically a 

 little pectinate, and of very thin texture, appears to constitute the first maxilla. 



Second Maxilla}. — These appear to be like the first pair, except that the plate is 

 broader and not apically pectinate. The delicacy of these organs makes it difficult to 

 separate them from the maxillipeds and mandibles without injury or distortion, the bases 

 of all being pretty firmly united. 



Maxillipeds broadly boat-shaped, the first joint narrow, the second very broad ; the 

 inner plate with a small depression in the centre of the distal margin, a small embedded 

 spine on either side of and below the depression, and a little lower down a pair of 

 spinules ; the outer margin of the plate, as also the margin of an inner ridge, is finely 

 pectinate ; the outer plates are broad at the base, apically narrow, the outer margin 

 convex, the inner very sinuous, minutely pectinate, except at a little emargination not 

 far from the apex ; the surface shows three minute spinules. 



First Gnathopods. — Side-plates small, with a downward produced lobe in front. 

 First joint widely expanded in front, not much longer than broad, the hind margin 

 nearly straight, but the front very convex; the second joint small, not longer than broad ; 

 the third joint not longer than the second, and as seen from the outer side not so long, 

 apically pointed, the hind margin carrying two small distally feathered spines ; the 

 wrist about half as wide as the first joint, but about twice as wide and nearly twice 

 as long as the third joint, with three distally feathered spines at the apex of the 

 straight hind margin, the front margin convex ; the hand, including the acutely produced 

 feathered process which forms the hinder apex, is equal in length to the wrist, but much 



