52 THE VOYAGE OF H.M.S. CHALLENGEE. 



of Serolis cornuta arc shown on PL I. figs. 7 and 8. The right mandible (fig. 7) has 

 ujion the upper surface a broad chisel-like process which is absent from the left ; the latter 

 is compensated by two large bifid spines instead of the single spine which springs from the 

 lower surface of the right mandible. In another specimen, however, these conditions were 

 reversed, the chisel-like plate being developed only upon the left mandible, while the 

 right mandible had two spines. 



T\\<i first pair of maxillcB are quite like those of other species. 



The second pair (PL I. fig. 9) in one specimen were asymmetrical like the mandible ; 

 the middle lobe of the left hand maxilla had four spines, while the right hand one (PL I. 

 fig. 10) had only two; in another specimen, however, both right and left maxillas had only 

 two spines. 



The maxillipedes (PL I. fig. 11) are very much covered with hairs ; the stipes, which 

 is separated from the lamina by a complete suture, is squarish in outline ; the palp is 

 broad and flat, the second joint distinctly cordate in outline. 



The second ixiir of ambidatory limbs in the male is modified in the usual way ; a 

 single spine similar to those which are found upon the inner margin of the penultimate 

 joint of these appendages is also found on the inner side and close to the distal end of 

 each of the two preceding joints. 



The remaining ambulatory limbs are in no way remarkable ; they are more like those 

 of Serolis schythei than any other species ; the first joint is the longest and broadest ; the 

 second joint is narrower and slightly shorter ; it increases in width towards the distal 

 extremity, which is furnished with a tuft of comparatively delicate spines and hairs ; the 

 third and fifth joints are subequal in size, while the fourth is a trifle longer ; large sword- 

 like spines mingled with smaller ones, and a very few serrated spines, are arranged in 

 tufts on the inner and outer sides of the distal extremity of these joints, and a few along 

 the outer margin. 



The three anterior abdominal appendages of the female are displayed in figs. 12-14 

 of PL I. ; as in Serolis septemcarinata and others the basal joint of the first (fig. 12) 

 has three branched hairs like those which clothe the outer margin of the exopodite and 

 endopodite of the same appendages, but smaller ; the second and third of these appendages 

 (figs. 13, 14) have two hairs instead of three. 



The suture upon the exopodite of the fourth pair of abdominal appendages is 

 oblique. 



The uropoda are attached about half way down the caudal shield, and extend as far 

 as its termination, the exopodite does at least, being almost half again as long as the 

 endopodite ; the outer margins of both, and the distal extremity of the inner margin are 

 serrated and beset with branched hairs. 



Station 149, January 9, 1874 ; lat. 49° 8' S., long. 70° 12' W. ; 25 fathoms ; bottom, 

 volcanic mud. January 13, Betsy Cove, Kerguelen Island. 



