210 PROFESSOR CHARLES C1IILTON ON THE 



mens, nor of the sexual differences, but states generally that the length of the 

 flagellum of the antennae and of the cleft in the telsou varies with age. 



It will be seen that, as STEBBING points out, this Antarctic species is very close to 

 E. propinquus of northern seas, and probably AALKER is correct in definitely 

 identifying it with that species ; the resemblance, however, to other northern species, 

 e.g. E. longipes, is also very close, and I think it will be better in the meantime to 

 leave the southern form under a distinctive name. The differences between all the 

 described species of the genus are very slight, and probably further research will lead 

 to a reduction of the number. 



E. laevis Walker was described from a single specimen, the size of which is not 

 given ; from the shortness of the flagella of the antenna? and of the projections of the 

 carpus, and from the absence of dorsal teeth, it seems likely that it was an immature 

 specimen, perhaps belonging to this species. 



With regard to E. microps Walker I do not feel able to express any definite 

 opinion ; some of the specimens were of large size, and the long antennae would indicate 

 that they were females, but, on the other hand, the telson is only very slightly cleft. 



M. CHEVREUX has recently (191 IB, p. 405, fig. 3), described another species, E. 

 bouvieri, from the South Sandwich Islands, but in view of the variations in this species 

 described above, it seems doubtful if the differences noted in the dorsal margin of the 

 first segment of the urus, and in the smaller depth of the cleft of the telson, are of 

 very much importance. His single specimen was an ovigerous female, but has the 

 short antennae which appear to be the mark of the male as pointed out by CHEVREUX 

 himself in E. laticarpus. 



Eusirus splendidus, sp. nov. (PL II. fig. 20.) * 



South Orkneys, Scotia Bay, Station 325. 15th August 1903. 54 fathoms. Two 

 specimens, both males : No. 1, 30 mm., No. 2, 35 mm. in length of body. 



First four segments of perseon slightly compressed ; hinder portion of body much 

 compressed, carinate, with pronounced dorsal teeth projecting backwards on the three 

 last segments of peraeon and on the three segments of pleon ; first segment of urus with 

 dorsal depression followed by slight carina on the posterior portion ; second and third 

 rounded. Side plates 1-4 slightly deeper than their respective segments ; first pro- 

 duced anteriorly into a rounded lobe reaching nearly to anterior margin of head, its 

 posterior angle with two or three teeth ; second and third rounded below, with two or 

 three small teeth at the posterior angle ; fourth broader, its posterior margin produced 

 into a subacute lobe below the fifth, lower margin rounded, posterior margin below 

 production serrate ; fifth with the posterior lobe deeper than the anterior ; sixth with 

 the posterior lobe produced downwards, much deeper and broader than the anterior ; 

 seventh, small, rounded below, not divided into lobes. Epimeral plate of the first pleon 

 segment narrowly rounded below ; second, much broader, rounded anteriorly, posterior 



* Probably the same as Eusirus perdentatus Chevreux (Bull. Museum Hist. Nat., 1912, No. 4, p. 10). 

 (BOY. soc. EDIN. TRANS., VOL. XLVIII., 492.) 



