HYDEOZOA — RITCHIE. 867 



branch commences with a series of about six athecate internodes, 

 bearing a single median sarcotheca on the anterior surface. 



Dr. Billard regards Aglaophenia acanthocarpa and Aglaophenia 

 laxa, both described by Allman,'^^ as ideiitical with AglaopJienia 

 divaricata. With this opinion I cannot agree ; for Alhnan ha& 

 described the presence of, and has figured very distinctly " an 

 imperfect septum continuous with the intratliecal ridge, and 

 anotlier oblique septum at the base of the lateral nematophores " 

 (p. 274) in Aglaophenia acanthocarpa; and "three distinct 

 diaphragms — one of which is a continuation of the intrathecal 

 ridge, one at the base of the lateral nematophores, and one at 

 the base of the hydrotheca " (p. 276) in Aglaophenia laxa. But 

 one of the most characteristic features of Aglaophenia divaricata^ 

 as portrayed by Bale and as exhibited in the specimens collected 

 by the " Thetis," is the large size of the supracalycine nemato- 

 phores, which reaching downwards to the middle of the hydro- 

 theca, bring it about that the septum at their base and that 

 opposite the intrathecal ridge are one. 



Other features distinctive of this species are the very strong^ 

 chitinous ledge which projects into the hydrotheca, and on which 

 the more delicate intrathecal ridge rests, and the absence of a 

 bounding wall between the lower half of the hydrotheca and the 

 internode. Gonosome not present. 



Dimensions. — 



Hydroclade-bearing internode, length 0-26-0-31 mm, 



„ „ „ diameter 0-22-0-28 „ 



Hydroclade internode, length 024-0-26 „ 



,, ,, diameter 0'14-0'15 ,,, 



Hydrotheca, depth 0'165 „ 



„ breadth at mouth s* 0-15-0-18 „ 



Locality. — Station 54, within Jervis Bay; depth, 10 to 11 

 fathoms : bottom, seaweed and sand ; 20th March, 1898. 



Order STYLASTERINA. 



Family STYLASTERID^. 



STYL ASTER EXIMIUS, Saville Kent. 



Stylaster elegans, Duchassaing and MichelotLi, Supj)!. Mem, 

 Coral, des Antilles— Mem. Acad. Sci. Turin (ii.), xxiii., 1864^ 

 p. 68, pi. ix., fig. 4. (Name preoccupied, renamed). 



53 Allmau— Journ. Linn. Soc, Zool., xii., 1876, pp. 274-276, pi. xxiv. 



54 Distance from posterior wall to anterior tooth. 



