1098 THE VOYAGE OF H.M.S. CHALLENGER. 



Upper Antennse similar to those of Gammaropsis exsertipes ; but the first joint of 

 the primary flagellum not the longest, and the secondary flagellum not so slender, con- 

 sisting of six joints, together equal in length to the first four or five of the primary, the 

 terminal joint minute. 



Lower Antennse in general as in Gammaropsis exsertipes, but with the fifth joint 

 longer than the fourth, the spines stronger, especially on the flagellum, the three terminal 

 joints of which have each a pair of short spines with accessory threads, the upper joints 

 having both longer and shorter spines similarly furnished. 



Upper Lip. — The distal border appears to be evenly convex. 



Mandibles. — The cutting edge with five or six teeth ; the secondary plate on 

 the left mandible with four teeth, that on the right mandible slighter, with the 

 edge much subdivided, with two principal teeth below, and several denticles above on 

 the edge facing the principal plate ; the worn plate has more denticles than the one 

 in preparation ; the spine-row has on the left mandible ten, on the right nine, long bent 

 denticulate spines, those nearest the cutting plate very broad ; the molar tubercle 

 prominent, with long denticles round the crown ; the first joint of the palp short, widest 

 distally; the second joint long, the front margin fringed with many spines of different 

 lengths, the hind margin also having five or six groups ; the third joint not so long as 

 the second, but long, expanding distally, with many groups of long spines along the hind 

 margin, and having the rather broad distal margin set with many long spines, the series 

 also passing down nearly to the base of the inner margin, many or most of the spines of 

 the third joint being strongly pectinate. 



Lower Lip. — The principal lobes forming a definite angle at the meeting of the distal 

 and inner margins, at which point there are two small spines ; the inner lobes widest 

 below the distal margin ; the mandibular processes long and narrow. 



First Maxillae. — Inner plate small, with eleven plumose setae along the sinuous 

 inner margin and a short seta at the narrow apex ; the outer plate with nine or ten 

 spines on the distal margin, variously denticulate, some on the outer and some on the 

 inner margin, and some apically ; the first joint of the palp short, with a spine near the 

 apex of the outer margin ; the second joint long, slightly widening from the base, 

 reaching beyond the outer plates, the distal margin having seven spine-teeth, the outer- 

 most the longest, the rest serrate on the outer margin ; on the surface below these are 

 seven slender feathered spines. 



Second Mo.xillie. — The inner plate shorter and a little narrower than the outer, with 

 a series of twenty plumose setae beginning near the base of the inner margin and passing 

 across the surface towards the outer apex ; the inner margin is also fringed with spines 

 from below the middle, and feathered or pectinate spines pass almost round the apex ; 

 the outer plate has the apex set with many long spines, but there are none on the 

 lateral margins. « 



