1010 THE VOYAGE OF H.M.S. CHALLENGER. 



of sixteen joints in the specimen which had twenty-eight joints in the upper flagellum, 

 of eighteen in that with thirty -three. 



Upper Lip. — The distal portion almost semicircular, the central part of the margin 

 furred. 



Mandibles. — The cutting plate divided into five teeth ; the secondary plate of the 

 left mandible very similar to the principal, with its edge divided into four teeth ; the 

 secondary plate of the right mandible bifid, with four or more noticeable teeth or 

 denticles above the two slender apical teeth, the group forming rather a bunch than 

 a row as on the other mandible ; spine-row of nine or more closely-set curved 

 denticulate spines ; molar tubercle massive, with an irregularly oval denticulate crown 

 and a plumose seta ; there is a process between the molar tubercle and the palp ; palp 

 set well forward, the first joint subequal in length to the third, the second long, 

 concave on the outer margin, the inner margin and surface set with slightly feathered 

 spines, some of them very long ; the short third joint having a group of small spines 

 about the middle, and a group .of still longer ones at the apex, almost all of these 

 spines being much longer than the joint. 



Lower Lip. — The front lobes having a little projecting point where the distal and 

 inner margins meet, strongly ciliated on both those margins, dehiscent, the space 

 partially filled by the thick oval inner lobes ; the mandibular processes divergent, the 

 ends a little ciliated. 



First Maxillse. — The inner plate with its whole inner margin from the apex 

 downwards closely fringed with some four and twenty plumose setaa ; the outer plate 

 having on the truncate margin nine spines, three of which are furcate, with a denticle 

 within the fork, two or three have a single tooth below the apical, and the rest are 

 pectinate ; the first joint of the palp more than half the length of the second ; the 

 second not dilated, having several slender spines on its truncate margin, and several 

 submargiual spines. 



Second Maxilla}. — The inner j^late not narrower but a very little shorter than the 

 outer, with a long row of plumose setae, beginning low down on the inner margin, and 

 passing towards the outer apex, in a large specimen numbering twenty-nine ; the apex 

 is crowded with long spines, of which there is a row down two-thirds of the inner 

 margin ; the spines on the apex of the outer plate are as usual longer than those of the 

 inner, the apical margin slopes outward, being there occupied, not, as often, with short 

 spines, but with long ones that are plumose, and almost by their tenuity and flexibility 

 deserving to be called setae. 



Maxillipcds. — The inner plates broad, reaching much beyond the first joint of the 

 palp, with a row of plumose setae beginning on the upper part of the inner margin and 

 passing along the surface to the middle of the apical ; the apical margin truncate, with 

 a strong tooth at the inner corner, below which is a curved pectinate spine-tooth, two 



