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



edge with eight or nine hairs instead of the usual two. In this respect Serolis gaudichaudii 

 seems to resemhle Serolis convexa{cf. Audouin and Milne-Edwards, loc. cit., pi. i. fig. 11). 



The maxilUpedes (fig. 15) are of the usual shape; the lamina is furnished with a 

 number of long hairs upon the lower surface, and the second joint of the palp has a row 

 of similar hairs upon the lower surface, some way from the external margin, which, as 

 usual, has another row of hairs. The third joint of the palp is extremely small, and I was at 

 first inclined to think that this was a mere accident, and that the terminal joint of the 

 palp had been recently broken oS", but since Milne-Edwards and Audouin figure ' the same 

 condition in Serolis gaudichaudii, it appears to be characteristic of these two species. 



The second pair of thoracic appendages are figured on PI. VI. fig. 1 ; the tuft of 

 hairs (a) have already been noticed as peculiar to the males ; several of the spines forming 

 the inner surface of the penultimate joint are more highly magnified in fig. 11 ; the 

 longer spines, instead of being bifurcate, as is the rule, terminate in a gradually narrowing 

 extremity, the posterior margin of which is beset with a dense row of fine branches. 



The third pair of thoracic appendages of the male are shown in PL VI. fig. 9 ; the 

 terminal joint is comparatively narrow ; from the inner margin arise some eight pairs 

 of conical spines, the axis of which projects beyond the termination as a short filamentous 

 recurved process. 



The remaining thoracic appendages were all more or less damaged, with the exception 

 of the sixth, which is figured on PI. VI. fig. 12 ; the second, third, fourth, and fifth joints 

 of this appendage are each furnished on the inner side wdth a tuft of fine pinnate hairs 

 like those on the second pair of appendages in the male ; on the distal border of the fourth 

 joint is a row of sharp serrated spines ; the terminal claw-like joint of the appendage is 

 sharply bent upon itself at right angles ; in Serolis gracilis and other species those 

 appendages in the males are similarly modified. 



In the anterior abdominal appendages the basal joint is triangular in shape, and the 

 projecting (lower) angle is furnished with three plumose hau's in the first of these 

 appendages, and two in the second and third as in many other species. 



The opercida are traversed by a suture at right angles to the long axis. 



Port William. Falkland Islands, 5 to 12 fathoms. 



3. Serolis schythei, Liitken (PI. II. figs. 5-13). 



Sei-olis schythei, Liitken, Vidensk. Meddel. f. d. nat. Foren. i Kjpbenhavn, 1858, p. 98, Tab. i. 



figs. 12, 13. 

 Serolis schythei, Grube, Arcbiv f. Naturgesch., 1875, p. 220, pi. v. fig. 1, pL vi. fig. 1. 



This species was originally described from a male specimen by Liitken. Grube in his 

 Monograph of the genus added some details to Liitken's description, and pointed out the 

 difi"erences that exist between the males and the females. 



' Tab. cit., Am. 12, 13. 



