THE SIPHONOPHORA. 349 



triangular, the ventro-lateral irregular in outline. Of these, only dorso- and ventro- laterals 

 extend to the apex. The ventral ridge does not branch, and there is no true ventral 

 facet, although Lens and Van Riemsdijk speak of the hydroecium as such. Each ridge, 

 except the ventral, terminates in a pronounced tooth, and there is in addition a tooth 

 breaking the basal outline of the median lateral facet. 



The nectosac extends upward slightly beyond the mid-level of the nectophore, and 

 is rounded apically. In the Biscayan material it is somewhat longer than in the 

 Pacific specimens. But in view of the possibilities of distortion through contraction, 

 and of the fact that all of the specimens are more or less battered, such a slight dilference 

 does not justify specific separation. The course of the subumbrellar canals is of the 

 usual type. 



The hydroecium reaches to about the same level as the nectosac, not to the apex as 

 described by Lens and Van Riemsdijk. Along its ventral face it is open for its whole 

 length, and its deepest point is opposite the mid-level of the nectosac. 



The somatocyst is of peculiar form, in that shortly above its point of origin it becomes 

 mach dilated and then contracts once more to run as a narrow tube nearly to the apex. 

 In the form of this dilatation there is a slight difference between Biscayan and Pacific 

 specimens. In the only one of the latter in which it is intact it is spherical. In four 

 of the Biscayan specimens it projects on either side in a short transverse horn. In one 

 Atlantic specimen, however, the horns are so much smaller as to suggest a transition to 

 the condition in the Pacific material ; therefore I consider this divergence of no more 

 importance than the slight difference in the form of the nectosac in the two collections. 



The identification of ttie inferior nectophores listed above, all of which were detached, 

 is made certain by their close resemblance to the corresponding nectophores of two 

 entire colonies in the ' Albatross ' collection. Their general form, especially the open 

 hydroecium, covered only near the apex by two short flaps, the six prominent ridges 

 (only four at apex), and the asymmetry of the basal teeth, of which the right ventral is 

 much the largest, still serve for identification. In both nectophores the unusual 

 prominence and brownish colour of the ridges, already noted by Lens and Van Riemsdijk 

 and very noticeable in the ' Albatross ' specimens, form good external field marks for 

 this species. 



Chutiiphyes has never been taken on the surface ; the • Albatross ' records are both 

 from 300-0 fathoms. 



The present captures show a range, at the least, from 1000-250 fathoms. Especially 

 instructive are the closing-net records of 1250-1000, 2000-1000, and 1500-750 fathoms, 

 since, of course, they show that the material actually came from these zones. How near 

 this species may have come to the surface cannot, of course, be absolutely determined. 

 But its absence from aU hauls from depths of less than 250 fathoms suggests that the 

 latter level is near the upper limit of its distribution. The number of specimens taken 

 is far too small to justify any conclusion as to its relative abundance at different 

 depths. 



