180 DR WALTER M. TATTERSALL ON 



The antennal peduncle extends anteriorly about half way up the distal joint of 

 the anteunular peduncle. 



The antennal scale (Plate, fig. 12) overreaches the antennular peduncle con- 

 siderably, and is three times as long as broad, the broadest portion before the middle. 

 The outer margin is almost straight and ends in a prominent spine, beyond which the 

 apex of the scale is slightly produced. 



The telson (Plate, fig. 13) is three times as long as broad "at its base, and has the 

 terminal cleft one-quarter of the entire length. The lateral margins are armed with 

 about thirty-six small spines, the first of which occurs about one-third of the way 

 down the margin. The spines are proximally arranged in small series of two and 

 three, but distally the last ten or a dozen spines are of equal length and not arranged 

 in series of shorter and longer spines. The lateral lobes of the apex of the telson are 

 armed with three strong spines, the outermost one of which is the longest. 



The inner uropods (Plate, fig. 13) are about one-sixth as long again as the telson, 

 without spines in the region of the otocyst. The outer uropods (Plate, fig. 13) are 

 longer than the inner. The proximal portion of the outer margin, without spines or 

 setae, is about two-ninths of the length of the entire margin, and has two spines at its 

 distal corner. 



This species comes remarkably near to B. siltogse, Hansen (1910), but differs in 

 the more produced rostrum and in the shape of the antennal scale. 



In B. sibogai the rostral plate does not extend nearly as far forward as the 

 anterior level of the eyes, and its margins meet in an obtuse angle. In B. Brucei the 

 rostrum extends almost as far forward as the anterior level of the eyes, and its margins 

 meet in an acute angle. 



In B. sibogse the spine on the outer margin of the antennal scale overreaches 

 the apex of the scale. In B. Brucei the reverse obtains. B. sibogiv is a deep-water 

 tropical species, B. Brucei a definitely Antarctic form. 



B. Brucei also comes very near to B. rostrata, Illig (1906) ; but, so far as the latter 

 has been described, it differs from B. Brucei in the different form of the antennal 

 scale and the different armature of the telson. 



I dedicate this new form to the leader of the Scottish National Antarctic Expedition, 

 whose intrepid researches have brought it to light. 



Sub-family SIRIELLIN^E, Norman. 

 Genus Siriellct, Dana. 



Siriella Thompsonii, H. Milne-Edw. 

 Scotia. 



Station 11, lat. 23 50' N., long. 21 34' W., tow-net. One. 

 Station 12, lat. 22 19' N., long. 22 07' W., tow-net. Five. 

 Station 13, lat. 21 58' N., long. 22 26' W., tow-net. One. 



(ROY. SOC. EDIN. TRANS., VOL. XLIX., 870.) 



