456 



THE VOYAGE OF H.M.S. CHALLENGER. 



The mandibles are seen in the form of curved plates with a serrate incisive margin 

 (fig. 57). 



The first pair of maxilla? is three-lobed ; the first lobe is on the inner side 

 of the first or coxal joint, and is crowned with four long stiff hairs; the second 

 lobe springs from the basis or second joint, and is broad, foliaceous, and crowned 

 with seven or eight strong stiff hairs or spines ; the third lobe consists of three small 

 cylindrical joints, each of less diameter than the preceding, and furnished each with two 

 hairs ; those at the extremity being the longest. These three joints appear to represent 

 the basis, ischium, and meros of the typically developed appendage. 



The second pair of maxilla? consists of a single biarticulate branch ; the basal joint is 

 long, broad at the base, and tapers towards the extremity, it is divided on the inner 

 surface into five lobes, the largest at the base, the smallest towards the apex, and each 

 is furnished with three long hairs, except the distal one, which has two ; the second 



Fig. 58.— First maxilla. 



Fig. 59. — Second maxilla, from drawings 

 by v. Willemoes Suhm. 



Fig. 60.— Maxilliped. 



joint is bilobed, the proximal lobe being furnished with one hair and the apical with 

 three. On the outer margin there is supposed to be an appendage of some sort, as seen 

 in the previous and in future stages, but Suhm says that he could not find it in three 

 specimens that he examined. 



The next succeeding pair of appendages is the third siagnopoda or the maxilliped ; 

 this Suhm figures as being biramose, the branch springing from the third joint, instead 

 of from the second or basis as is usual. This appendage consists of six joints and 

 a small ecphysis, furnished with several long hairs. 



The first pair of gnathopoda has the basisal joint long and robust, carrying two 

 branches, one of which, composed of four joints, is the true limb, and the other a 

 multiarticulate branch. 



