Yuuiiif Staijts vf L'liibcllulaiia. 315 



auotlier ttjniiiiial polype, which \6 etfected by the tirst polype 

 (hitherto at the top; being removed a little towards one side ; 

 and we now get an ari'angement {^^. 4) in which there is a 

 })olype close to the top on each side of the end of the rachis, 

 or they both grow out at right angles from the latter ; and 

 the pol}q)aiy now, as in fig. 2, presents a perfectly symmetrical 

 arrangement, viz. two polypes on one side and two on the 

 other. 



The f'lid of the rachis is clearly visible in fig. 1, which has 

 l)een drawn from a specimen made transparent ; and it is in- 

 dicated by a knob in fig. 2. S/jicula were not visible in fig. 1 . 

 Zooids are first to be seen on the ventral side of fig. 2, and so 

 they are in fig. 3 ; in the largest of the specimens here figured 

 they cover the ventral side of fig. 4 «, but leave free a middle 

 line on the dorsal end of the same. 



The mode of growth of the polypes in this Antarctic 

 Vmbelhdaria is therefore, so far as our specimens show, as 

 follows : — 



1. The terminal polype comes out (fig. 1). 



2. The terminal polype grows, and two lateral ones come 

 out (figs. 1 and 3). 



3. The terminal pol}'pe loses its place by another one coming 

 out, and is removed towards the side (figs. 2 and 4). There 

 are now on each side a terminal and a lateral polype (according 

 to Lindahl's nomenclature). 



4. A fifth ])olype is coming out in the centre of the poly- 

 pary (fig. 2 i, ill.) ; and the rest of the polypes very likely 

 come out below the first two lateral ones. 



In the earliest stage there are neither spicula nor zooids ; the 

 latter, when they have come out, leave a line free on the dorsal 

 side of the polypary. 



H.M.8. ' Challenger,' 

 Manilla, January 1870. 



EXPLANATION OF PLATE X\TII. A. 



All the figures give the natural size of the polypes. In tig. 1 the 

 rhachis ha« been put in as seen by a low magnifying-power. Letters 

 the same in all the figures : — t = terminal poh'pes ; i. and ii. = lateral 

 polypes ; iii.= third lateral or fifth polype ; z = zooids. 



Fiys. 1-4. Young stages of I'mbellnhin'us^.?, found near the antarctic 



ice-barrier, lat. 02° 26' S., long. 95° 44' E., in a depth of 1976 



fathoms. 

 Ftp. 1. From the ventral side. Length 41 millims. 

 Ftp. 2 a, from the ventral side ; 2 b, from the dorsal side. Length. 



52 millims. ; length of polypes 7-><l millims. 

 Fif/. 3. From the ventral side. Length 100 millims., of polypes 11 millims. 

 Fif/. 4 n, from the ventral side ; 4 b. from the dorsal side. Length 



385 millims., of polypes \-') millims. 



