1204 THE VOYAGE OF H.M.S. CHALLENGER. 



left it resembles the principal plate in general structure ; the spine-row of nine denticu- 

 late spines; the molar tubercle prominent, with a strong circlet of teeth round the 

 crown, the outside of which is strongly ciliated ; a round-headed process rises not far 

 from the base of the palp ; the first joint of the long palp longer than broad, with 

 convex outer margin, the second joint long, strongly fringed with numerous pectinate 

 spines on both margins, the groups being planted chiefly on the outer surface ; the 

 third joint long, curved, shorter than the second joint, fringed for almost the whole 

 length of both margins and at the narrow apex with groups of spines, the concave 

 inner margin having a close row of short spines, besides the less closely set long ones. 



Lower Lip. — The principal lobes distally broadly rounded and loosely ciliated ; at the 

 junction with the inner margin there are two minute spines, making a kind of apex ; 

 lower down on the inner margin are two more ; the inner margin is not strongly ciliated, 

 except at the basal part, where the crowded cilia become almost spine-like ; the inner 

 lobes are distally broadly rounded and closely furred ; the mandibular processes 

 moderately prominent, a little divergent, the apex rounded. 



First Maxillse. — The inner plate narrowing to the rounded apex on which there 

 are four plumose setae, one smaller than the other three ; the broad outer plate has on 

 the slightly convex distal margin eleven spines, of which seven are rather long and 

 slender, with two or three lateral denticles on the inner side, the innermost spine having 

 two or three little denticles also on the outer side ; the other four spines are shorter, 

 with a furcate appearance, the apex bending inwards and having on the outer side two 

 unequal lateral teeth ; the first joint of the palp is short, the second is long and broad, 

 reaching beyond the outer plates, broader distally than at the base, with a series of 

 twenty or more spines passing round the broad distal margin and some little way 

 down the inner, those on the inner margin being slender, the others being spine-teeth ; 

 submarginal to these are about fifteen slender spines ; eight or nine slender spines 

 fringe the convex outer margin, the surface carrying six or seven more. 



Second Maxillse. — The plates broad ; the inner shorter than the outer, nearly as 

 broad, with plumose setae along most of the straight inner margin, and some on the 

 surface near the apex, which is broadly rounded, fringed with short spines which stop 

 short of the outer slope ; the outer plate is wider distally than at the base, the 

 spines beginning below the middle of the inner margin, one series passing round within 

 the broad rounded distal margin, another passing round the margin, some of the spines 

 being very long, though a few at the outer extremity are comparatively short. 



MaxilUpeds. — The inner plates broad, not reaching beyond the first joint of the 

 palp, the inner surface having a triangular space covered with spines, the distal margin 

 broad and flat, carrying three spine-teeth and many slender spines ; the outer plates 

 not nearly reaching the end of the second joint of the palp, the inner margin carrying 

 about a dozen slender spine-teeth, and the apical margin half-a-dozen; there are besides 



