OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 291 



present species because Fabricius describes the carapace as smooth, without mention 

 of the little tooth on the gastric region. But, at the date when Fabricius wrote, 

 such a tooth might easily have escaped notice or not have been thought worth 

 mentioning as interfering with the general smoothness of the carapace. On the 

 other hand, among the Malacostraca frequenting the Gulf weed there is, I believe, 

 no other species with a smooth, apically quinquedentate rostrum such as Fabricius 

 assigns to his P. fucorum, so that I cannot agree with Ortmann's verdict in 1893 

 that it is a quite apocryphal species. So far as I have observed, the serration of the 

 apex has five points more frequently than any other number, but the variation 

 extends from one to nine, the only number within these limits that I have not found 

 being eight. The antero-lateral corners of the carapace are serrate, according to Bate 

 with five or six points, according to Kathbun with five to eight. In one of our 

 specimens there were seven points on one corner and eight on the other. Another 

 specimen has eleven points on one side ; those on the other side were not counted. 

 Fabricius gives the size as only a third of P. squilla, which well suits the present 

 identification, as the length of L. ensiferus varies in different estimates from half an 

 inch to an inch. Of those taken at Station 539, it was recorded that one was quite 

 blue, two others brown and blue. 



Localities.— Gulf weed, Stations 532, 533, 537, 538, 539, between 18° 43' N., 

 27° 46' W., and 33° 53' N., 32° 27' W. 



Some specimens were seen to be infested by the minute Bopyrid Bopyrina 

 latreuticola (see p. 301). 



Genus Nauticaris, Bate. 



1888. Nauticaris, Bate, Rep. Voy. "Challenger," vol. xxiv. pp. xii, 577, 602. 

 1893. ,, Stebbing, Hist. Crust., Internat. Sci. Ser., vol. lxxiv. p. 234. 



1902. Merhippolyte, Hodgson, "Southern Cross" Exp., "Crustacea," p. 233. 

 190fi. Nauticaris, Caiman, Ann. Nat. Hist., ser. 7, vol. xvii. p. 30. 



In Calman's synopsis of the Hippolytidx this genus is distinguished as having 

 arthrobranchise at the bases of the first four pairs of perseopods, mandibles with palp 

 but without cutting edge, wrist or fifth joint of second perseopod with more than 

 seven subdivisions, and a movable spine at the base of the uropods. The last of 

 these characters seems to be obscurely expressed, since the spine-like process on the 

 peduncle of the uropods is not movable, and the movable spine is at the infero-lateral 

 hind corner of the sixth pleon segment. This spine is said by Bate to be absent 

 from his species N. unirecedens, though he includes it in his account of the genus. 

 But de Man (1907) and Calman agree in identifying N~. unirecedens with the earlier 

 Hippolysmata vittatus, Stimpson. Dr Calman points out that Hippolyte magellayiicus, 

 A. Milne-Edwards, 1891, belongs to Nauticaris, but differs from other species in 

 possessing exopods on the third maxillipeds. He finds that Merhippolyte australis, 

 Hodgson, 1902, is synonymous with N. marionis, Bate, Hodgson having been misled 

 partly by my acceptance of Bate's error as to the second pereeopods and partly by 



