DESCRIPTION OF SPECIES 3°? 



The maxilliped (Fig. 2 a) has the basipodite completely fused with the lamella, the 

 fusion being continued beyond the attachment of the basal joint of the endopod, so that 

 the latter appears to spring from the centre of a plate-Uke structure. A similar arrange- 

 ment occurs in S. carinata, Lockington. 



The second, third and fourth thoracic appendages of the male are shown in Figs. 

 ID b-d. The propodus of the second appendage is broadly oval with its inner margin 

 armed with a row of about thirty short stout spines : these spines (Fig. lob) are inclined 

 slightly backwards, and each consists of two branches the posterior one of which is the 

 longer; a series of rather long setae flank this row on either side. This and S. nototropis, 

 n.sp., are the only species in which the propodus bears only one variety of modified 

 spine on its inner margin ; for although Collinge (p. 75) failed to find more than one type 

 in S. septemcarinata, Miers, the observations of Beddard, Hodgson and Tattersall on this 

 species show that in reality there are two. Another character peculiar to this species is 

 the presence, in the adult male, of a dense covering of long delicate hairs on the outer 

 distal part of the propodus of this appendage. The distal truncate end of the carpus 

 bears two stout spines, each with a bifid extremity, and a number of simple setae. The 

 third thoracic appendage of the male (Fig. \o c) is considerably longer though more 

 delicate than the second. The propodus is only slightly broader than the carpus; it has 

 eleven spines of the usual type on its inner margin, arranged in three rows^two lateral 

 ones of four spines each, three of which are placed near the proximal and one near the 

 distal end of the propodus, and a median row of three, placed in a position intermediate 

 between the distal and the proximal spines of the lateral rows. The dactylus terminates 

 in a stout spine, the tip of which is slightly curved outwards. The last pair of thoracic 

 appendages is shorter and more delicate than the others. 



In each of the three sternal plates of the abdominal segments in both sexes the median 

 posterior border is produced into a spine which increases in size from before backwards. 

 The protopodite of the first three pairs of pleopods is somewhat triangular, with the 

 produced angle bearing three plumose setae on the first, and two on each of the second 

 and third pleopods. The appendix masculina on the second pleopod of the male reaches 

 about two-thirds of the way towards the apex of the terminal segment. The exopod of 

 the fourth pleopod has a transverse suture and a fringe of plumose setae along its outer 

 margin ; the endopod is entire and with a transverse suture. 



The uropoda extend nearly to the tip of the terminal segment. The protopodite, as 

 usual, has its inner distal extremity drawn out into a spine and the endopod is sHghtly 

 longer than the exopod; both have rounded distal ends, crenate and fringed with 

 plumose setae. 



Distribution. Off East Falkland Island, and between 66° and 58° W and 52° 55' S. 



This species appears to be most nearly related to S. carinata, Lockington, to which it 

 bears a fairly close resemblance. The following points are noted after comparison of the 

 two species: 



(i) Both species are of small size, the adult males measuring not more than 8 mm. 

 in length ; the shape of the body is broadly oval with a median dorsal keel. 



