1148 THE VOYAGE OF H.M.S. CHALLENGER. 



of the apex are numerous, but do not descend its outer slope ; the outer plate has the 

 inner margin smooth, slightly concave at the centre ; numerous long spines fringe the 

 apical border, which on the outer side becomes very oblique. 



Maxillipeds. — The inner plates reaching fully as far as the apex of the first joint of the 

 palp, having the usual plumose setae on the inner margin, the distal margins sloping in- 

 wards, carrying three strong but short spine-teeth and several feathered spines ; the outer 

 plates not reaching the apex of the second joint of the palp, having nine spine-teeth not very 

 closely set on the slightly crenate inner margin, and five spines round the serrate distal 

 margin, the two outermost too long and slender to be called spine-teeth; the first joint of 

 the palp short, its particularly short inner margin carrying a slender spine ; the second 

 joint more than twice as long as the first, with both margins convex, the inner having 

 in or near it many very long slender spines ; the third joint a little longer than the first, 

 the convex outer margin interrupted at some distance from the apex by a large row of 

 feathered spines, the distal half of the inner margin and the concave apical margin also 

 carrying spines ; the finger slightly curved and tapering to a blunt end, even with its 

 terminal spine scarcely so long as the third joint, the dorsal cilium very near the 

 hinge ; the ungual spine scarcely half the length of the trunk of the finger, attended by 

 three or four setules planted near the inner apex of the finger ; on one of the fingers the 

 ungual spine seemed to be in duplicate. 



The oval triturating organs of the stomach show round one side a row of about 

 sixteen spines with stout bases, and on the opposite side numerous slender spines, and 

 some like them on the surface between the two rows. 



First Gnathopods. — The side-plates less deep than broad, directed forwards, the lower 

 margin crenate and fringed with setae. The first joint almost entirely free from the side- 

 plate, the front margin almost straight and smooth, the hind margin convex, with some 

 long feathered setse above the centre and some apical spines ; the second joint short, with 

 spines in two or three groups near the apex of the convex hind margin ; the margins of 

 the third joint converging to a pointed apex which lies upon the wrist ; one group of 

 spines is near the middle of the hind margin, and two larger groups are between this and 

 the apex ; the wrist is not quite so long as the hand, distally nearly as broad, with four 

 groups of spines at the long convex front margin ; the free front of the hind margin 

 convex, serrate, closely fringed with spines, some groups also being inserted on the 

 adjoining surface ; the hand oval, nearly as long as the first joint, with four transverse 

 rows of long spines at the front margin, which is continuous with that of the wrist ; 

 there are several spines, singly and in groups, on the surface near the hind margin ; the 

 hind margin serrate, carrying five groups of spines before reaching the palm, and between 

 the apical group and that preceding it having a long and strong palmar spine ; the 

 palm itself convex, bordered with spines and spinules ; the finger fitting the palm, 

 with a dorsal cilium near the hinge, the inner border cut into many decurrent teeth. 



