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



Second MaxiUa;. — Outer plate longer and slightly broader than the inner one, 

 distally fringed with a mass of slender curved spines, the outer ones the longer ; the 

 inner plate has the distal fringe of short spines passing in an even curve some way 

 down the inner margin to a plumose bristle much longer and stouter than the spines ; 

 below this there are some hairs, as there are also on the other margins of both plates. 



MaxiUipeds. — Inner plates rather long, with plumose bristles passing up the inner 

 margin, within the distal, and down part of the outer margin ; three short, strong teeth 

 on the distal margin, and one having its insertion just below the inner angle of the 

 plate. Outer plates short, not reaching beyond first joint of palp, short spines within 

 distal margin and upper part of inner margin ; other spines, of various sizes, but none 

 large, singly or in groups, on the outer side of this and the preceding joint. First 

 joint of j)alp with outer border much longer than the inner ; second joint distally lobed 

 on the inner side ; inner margin of this and the next joint fringed with short spines ; 

 all three joints with small rows of spines on the outer sides ; the fourth joint rudi- 

 mentary, a tubercle, tipped with spines. 



In the so-called triturating orgcm at the anterior end of the stomach a row of 

 twenty-eight spines is found, becoming longer and thinner at both ends of the row. 



First Gnathopods. — The side-plate almost concealed by that of the second segment ; 

 spines on its lower border, and on the inner side, and on an inner lobe where the first 

 free joint articulates. In the male, first joint broad except at its origin ; fourth joint 

 postero-distally lobed, much longer than fifth ; hand with a conspicuous postero-distal 

 lobe ; finger short, closing over the slightly concave palm so as to reach the inside of 

 this lobe ; distributed over all the joints on margins and surfaces are spines with sub- 

 terminal accessory threads ; a row of minute straight hairs on the palm ; and a stronger 

 spine where the tip of the finger closes down ; some fine spines on the finger at the 

 origin of the nail, where also the inner margin of the finger slightly projects. In the 

 female, the first joint almost parallel-sided, the fourth joint a long narrow triangle, with 

 hinder (especially the distal) spines prominent ; hand widening a little distally, the 

 finger projecting beyond the slightly convex palm. 



Second Gnathopods. — The side-plate fringed below with spinules ; the hinder margin 

 in this and the next two pairs of side-plates having a projecting process for purj)oses of 

 articulation ; branchial vesicle much broader than long, upper border very sinuous ; 

 in the male first joint shorter than hand, broadest near its origin, lower edge sUghtly 

 lobed ; second joint antero-distally lobed on the outside and medio-distally on the inside ; 

 third joint squared; wrist a small cup, almost lost in the outswelling of the hand 

 beyond it ; the immensely powerful hand broadest near its origin ; palm sinuous, bordered 

 with spines of various sizes, and forming a groove on the inner side into which the point 

 of the finger closes down ; the finger itself strong, inner margin fringed with spinules, 

 and forming a double concavity, that near the tip leaving an open space between finger 



