1172 THE VOYAGE OF H.M.S. CHALLENGER. 



Telson tending to circular, not reaching the apex of the peduncles of the third 

 uropods, having a small hook at each corner of the distal margin. 



Body little compressed. 



By the habit of body this and the following genus appear to belong to the Corophiidse, 

 but they are excluded from that family as defined by Boeck through having the third 

 uropods biramous. From the Photidae and Podoceridae Haplocheira is removed by the 

 gnathopods, of which neither pair is subchelate. 



Haplocheira plumosa, n. sp. (PL CXXVL). 



Body little compressed, narrowing from the third or fourth segment of the perceon ; 

 the rostrum small, acute, the lateral lobes of the head triangular, produced considerably 

 beyond the rostrum, acute ; the segments of the peraeon short, the first three of the pleon 

 successively longer, the third segment having the lower margin straight, long, equipped 

 with some submarginal setae, the posterolateral angles rounded, having a cilium in a 

 little notch. 



The Eyes small, oval, advanced into the lateral lobes of the head, with about thirty 

 ocelli, retaining dark colour in spirits. 



Upper Antennse. — The peduncle longer than the flagellum, not so long as the 

 peduncle of the lower antennae ; the first joint about as long as the head, as long as the 

 second and broader, with a group of tolerably stout spines and a slender one at the lower 

 apex, also a spine near the middle of the lower margin ; the second joint with some small 

 spines ; the third half the length of the second, and thinner ; the flagellum of nine or ten 

 joints, together as long as the second and third of the peduncle, equipped with cylinders ; 

 the secondary flagellum, apparently broken, showing one narrow joint, not tapering, not 

 so long as the first of the primary. 



Lower Antennae slightly longer than the upper. The first two joints short, but the 

 gland-cone rather long, decurrent, acute ; the third joint stout, scarcely longer than the 

 second including the produced gland-cone, with one or two spines on the convex upper 

 margin, a slender spine and spinules on the lower ; the fourth joint a little curved, longer 

 than the first joint of the upper antennae, carrying a few slender spines; the fifth joint 

 shorter and thinner than the fourth, almost as long as the first of the upper antennae ; 

 the flagellum of five joints, together not quite so long as the fifth joint of the peduncle, 

 the last joint minute, tipped with slender spines, the other four having each two groups 

 of spines, including one or more strong ones. 



Upper Lip. — The distal border with a very slight unsymmetrical emargination, the 

 tract on cither side of which is slightly ciliated. 



Mandibles. — The trunk broad, the cutting edge not very elongate, with four very 

 unequal teeth ; the secondary plate of the left mandible with two teeth as large as the 



