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



the apex ; outer plate with a double row of longer pectinate spines about its apical border, 

 with some short setse on the outer margin. 



Maxillipeds. — Inner plates not extending equally far with the first joint of palp, 

 bordered with long plumose setae on the inner margin, these passing over into plumose 

 spines on the squared apical margin which carries three broad teeth ; outer plate with 

 ten teeth along the serrate inner margin, a row of flexuous spines behind them on the 

 outer surface, plumose setse on the apical outer border, cilia round the remainder of the 

 curved outer border and on the surface of the plate. The first joint of the palp the longest, 

 reaching almost as far as the apex of the outer plate, so that the three remaining joints, which 

 successively decrease a little in length, project very prominently. All the joints of the 

 palp except the last are bordered on the inner side with plumose setse ; those which they 

 carry on the outer distal corners seem to be smooth ; the third and fourth joints are 

 ciliated on the surfaces ; the last has a single apical plumose seta and a smooth one on 

 the convex outer border. 



First Gnathopods. — Side-plate very small, rounded below ; first joint longer than all 

 the rest of the limb, hinder margin sinuous ; third joint furred on the hinder margin, a 

 group of slightly crooked spines near the apex ; wrist furred behind, subequal in length 

 to the hand, having on the hinder margin a row of spines pectinate on two edges ; hand 

 narrowed distally, the palm not very clearly defined, microscopically pectinate, set with 

 various spines and setee, a few of the latter occurring on the anterior borders and apices of 

 both wrist and hand ; finger microscopically pectinate on the inner margin, with a stumpy 

 spine and some cilia near to the nail. Of the spines on the palm some are strong, smooth, 

 curved at the tip, with the accessory thread near the end, others are slender and 

 pectinate. 



Second Gnathopods. — Side-plates small, oval, rather larger than those of the first 

 segment ; branchial vesicle at its base narrow, main lobe large, longer than the first joint 

 of the leg ; first joint as long as that of the first gnathopods, but much shorter than the 

 rest of the leg ; second joint much longer than the third, subequal in length to the wrist; 

 wrist longer than hand, furred on both margins, on the hinder margin adorned in a 

 remarkable manner with several rows of peculiar curved spines or setse, of very various 

 lengths, which thicken apically, there presenting something the appearance of the under 

 side of a horse's hoof, a thin striated wing on each side leading up to this termination, 

 the two transparent slightly overlapping ends producing the appearance mentioned ; on 

 the sides there are some pectinate pointed setse ; the oval hand is much furred behind 

 and distally in front, the armature consisting of remarkable spines as on the wrist, and 

 in addition rows of shorter spines bending in the opposite direction, that is, towards the 

 finger, distally pectinate, an accessory thread extending beyond the apex ; on both hand 

 and wrist the spines are graduated in length, increasing as they advance distally, so that 

 the tips form a regular curve ; the setiform spines on the side and infero-anterior corner 



