202 PROFESSOR CHARLES CHILTON ON THE 



The third uropod reaches a little beyond the peduDcle of the second ; its single branch 



is about as long as the peduncle, but rather more slender, and bears a minute second 



joint. The telson reaches slightly beyond the third uropod, is greatly flattened 



vertically, and has the dorsal border somewhat thickened, as described in T. tcalkeri. 



In many respects this species shows close approximation to T. herdmani, described 



by Mr Walker, from South Victoria Land, but is clearly distinguished by the large 



chelate second gnathopod. This may, however, ultimately prove to be a sexual 



character. 



Tliaumatelson herdmani Walker. 



Thanmatelson henhnani Walker, 1906, p. 15, and 1907, p. 21, pi. vii. fig. 11. 

 South Orkneys, Scotia Bay, Station 325. 1903. A few specimens. 

 After 1 had drawn up the description of the preceding species, with the remarks 

 thereon, I found in the " residues " of some collections made during 1903 both additional 

 specimens of that species and also others with subchelate second gnathopoda agreeing 

 in all respects with T. herdmani Walker, so that that species also does occur at Scotia 

 Bay. I can find very little difference between the two except in the second gnathopoda, 

 and, as stated above, strongly suspect that both forms belong to the same species ; but 

 the additional specimens came into my hands too late to allow of the question being 



fully investigated. 



Genus Bircenna Chilton, 1884. 



Bircenna crassi2yes (Chevreux). 



Wandelia crassipes Chevreux, 1906a, p. 87, figs. 1 and 2. 



1906b, p. 45, figs. 24-26. 

 Bircenna crassipes Chilton, 19U9b, p. 62. 



South Orkneys, Scotia Bay, Station 325; dredge, 9-10 fathoms. May 1903. 

 One specimen, 2 mm. long. 

 This small specimen agrees very closely with Chevreux's description and figures. 

 The species is very close to B. fulva Chilton from New Zealand, and differs from it 

 only in the longer and more slender gnathopods, and in having the branches of the 

 first and second uropods equal and shorter in proportion to the peduncles. 



Kurialoncjimana Walker and Scott (1903, p. 228), from tlie Indian Ocean, appears 

 to be nearest ally of the genus Bircenna. 



Genus Colomastix E. Grube, 1861. 



Colomastix brazieri Haswell. 



Colomastix hrazieri Haswell, 1880, p. 341, pi. x.xii. fig. 4. 

 Stebhiiig, 1906, p. 206. 



South Orkneys, Scotia Bay, Station 325. 1903. Two small females, the larger 



3 "5 mm. long. 



These specimens certainly belong to this genus, and probably to Haswell's species ; 



(roy. soc. edin. trans., vol. xlviii., 484.) 



