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



Harpinia obtusifrons, u. sp. (PI. LVL). 



Rostral portion of the head broadly rounded, reaching to the apices of the peduncles 

 of the upper antennaa. The head broad at the base, longer than broad, the sides 

 a little sinuous, with a conical plate underneath, situate outside the base of the 

 upper antennae; j)ostero-lateral angles of the third pleon-segment upturned, forming a 

 rather long sharp tooth, the lower boundary of a deep cavity in the hind margin 

 of the segment ; the sides of the sixth segment are produced some way along the 

 telson. 



Eyes not perceived. 



Upper Antennae. — First joint of the peduncle bulky, widest at the base, the inner 

 border smooth, convex, the other sinuous, with four broad distally feathered cilia at the 

 apex ; the second joint small, not twice as long as broad, with long setae and a plumose 

 cilium on the outer apex ; the third joint much shorter and narrower, with setas at the 

 apex on both sides ; the flagellum slender, of seven joints, the first the longest, a little 

 shorter than the second of the peduncle ; the secondary flagellum of five joints, nearl}^ 

 equal in thickness as well as length to the first five of the primary. 



Lower Antennse. — The first joint is bent round at right angles to its base, with a 

 distally narrowed process on the outer side, the piece which appears to correspond to 

 the coalescent second joint being rounded on the outer margin, not in any way produced 

 either conically or otherwise ; the third joint is nearly as long as the fourth, it has a 

 group of setaB on the lower part of the outer margin ; the fourth joint widens distally, 

 round the apical l^order armed with rows of long setse, setiform spines, and two stronger 

 spines, on the inner border above having a group of three small spines ; the fifth joint 

 much narrower and a little shorter, has a straight smooth inner margin, the outer 

 convex, armed with setae and two sjjines near the apex ; the flagellum shorter than the 

 peduncle, of eight joints, of which the first is the longest. 



Uiyper Lip widening to a broad distal margin. 



Mandibles with a longer trunk than in the genus Phoxocephalus ; the cutting edge on 

 the left mandible showing a tooth above, then a long oblique margin without prominent 

 dentation, ending with a bidentate apex, the whole plate being itself more or less tooth- 

 like ; the secondary plate broad, widening slightly to the front edge, which is cut into 

 six teeth, the lowest being the longest ; the spine-row is long, showing amongst some 

 accompanying cilia nine curved denticulate spines, the last a very small one ; the 

 molar tubercle appears to be rather broad, but weak in structure, and unarmed ; the 

 cutting edge on the right mandible has a tooth above, an oblique, slightly concave, 

 almost invisibly denticulate, margin, forming at the ajiex a large sharp tooth, with a 

 little one considerably in the rear below ; the secondary plate is very different from 

 that of the left mandible and much smaller, presenting below a spine-like tooth and 



