160 " ENUEAVOim " SCIENTIFIC RESULTS. 



The branchial base has its ventral margin inrolled in a 

 plane spire for about a circle ; the right and left bases arc 

 connected by a membrane which reaches to the level of the 

 origin of the filaments or radicles, of which there are 30 on 

 each side, rather thick and arising m a smgle series. 



The collar is on the ventral surface directed forwards so as 

 to cover the gill bases ; it is entire here, though in the median 

 line it is folded, which gives it the appearance of an incision 

 (PL xlviii., fig. 47). On each side close to the dorsal surface, 

 there is an incision separating a dorsal triangular lobe, 

 directed forwards, which is posteriorly continuous with the 

 thoracic membrane or " palhum." 



Partially hidden by this dorsal lobe is a separate " latero- 

 dorsal " lobe, slightly folded lengthwise, which is directed 

 forwards and extends slightly beyond the free edge of the 

 ventral lobe (PI. xlviii., fig. 43). this I take to be M'Intosh's 

 fan-shaped region. 



The first bundle of chsetse (collar chsetse) is widely separated 

 from the following dorsal bundles. It is situated at the 

 upper end of an oblique tongue-shaped ridge, seen through 

 the transparent " palhum " owing to its faint purple colour. 

 It runs upwards from the level of the torus uncinigerus of the 

 next segment, towards the apex of the dorsal collar lobe ; it 

 appears to be a support to this lobe or to the pallium (PI. 

 xlviii., fig. 48). 



The tori uncinigeri are so arranged on the thorax that 

 their ventral margins reach successively lower levels, thvis 

 a wide triangular area is outlined, with its open base forwards 

 and the apex situated on or before the last thoracic segment. 

 Gland shields occur within this area (PI. xlviii., fig. 47). 



The collar chsetse are about six in number, and have the 

 usual shape (PI. xlviii., fig. 50), though the basal denticulated 

 region is much more extensive than is shown in Marenzeller's 

 figure. 



In all the other features there is agreement witji that 

 species. 



Loc. — Off Babel Island, Bass Strait, 50-80 fathoms. 



Distribution. — Japan ; Hawaii. 



