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



are about a dozen spines, followed below by half-a-dozen plumose setse ; the apical 

 border of the outer plate set with spines curved at the tips, the longest at the outer 

 apex, followed by two or three short ones down the outer margin. 



Maxillipeds. — The inner plates reaching about as far as the apex of the first joint 

 of the palp, with three teeth on the apical margin, of which the outer is much the 

 smallest, and plumose setse on the inner margin passing over to the outer apex ; outer 

 plates reaching slightly beyond the second joint of the palp, the inner margin set with 

 teeth numbering from nine to ten, followed by two longer ones on the apical margin ; 

 eight or nine small spines may be seen on the outer surface of the plate, at a little 

 distance from the inner margin ; the palp compact, the second joint but little longer 

 than the first ; the third joint not longer than the finger, which is robust, ending in 

 a long, thin, sharp nail ; it has two cilia on the inner margin near the nail, and the 

 dorsal cilium not far from the base. 



First Gnathopods. — Side-plates a little widened and much rounded below ; first 

 joint projecting a little beyond the side-pla.te, of even width, with setae on the front 

 margin ; second, thu-d and fourth joints difi'ering but little in length, together scarcely 

 as long as the hand, the third oblong, the fourth triangular ; the hand large, increasing 

 in width distally, the palm a little sloping, defined by two spines, between which the 

 finger-nail closes down, the palm-margin crenate, with cilia just within the border and 

 setfe a little deeper within it ; the finger has a dorsal cilium near the hinge, and one 

 at the base of the nail, which in our specimen was broken. 



Second Gnathopods. — The side-plates narrow, slightly rounded below and scarcely 

 at all dilated ; the branchial vesicles broad except at the base, without folds. First joint 

 a little dilated and bent below, nearly equal in length to the third, fourth and fifth 

 united ; the second joint nearly as long as the wiist ; the third joint much shorter, equal 

 in length to the hand, furred behind, with some small setse near the apex ; the wrist 

 lightly furred on the distal half of the front and the proximal half of the hind margin, 

 below this on the dilated breast having tooth-like cilia or little incurved spinules, and, 

 in addition, numerous scale-like ornaments, not, I believe, uncommon in this family, 

 minute in size, fan -like in appearance ; the hand is furred, a quacbangular oval, the 

 lower part of the front and forepart of the apical margin occupied with the usual rows 

 of pectinate spines, the small finger being set on beyond these, and antagonizing with 

 the well-advanced point of the hinder margin of the hand, which is thickly set with 

 pectinate, geniculate spines. The dorsal cilium of the finger fixed about centrally, 

 projects over the tip of the finger. 



First Peneopods. — Side-plates a little dilated below, scarcely rounded ; first joint 

 just reaching the lower rim of the side-plate ; third joint much longer than fourth, 

 rather broader, scarcely produced ; fourth joint broader than fifth, but a little shorter ; 

 fifth joint with the hinder margin straight, with some spines ; the hind margins of the 



