322 ERNEST WARREN. 



This interesting" liydroid, wliicli in tlie juxtaposition of the 

 hydrothecje and in the absence of intervening internodes 

 approaches the St at op lea, is quite common on the Natal 

 coast, growing' on sea-weeds and worm-tubes. It has not, 

 however, been found in the reproductive stage. 



Trophoso3Ie. — Hydrorhiza, creeping stolon irregularly 

 branched. 



Diameter O'o03 mm. ; thickness of perisarc 26 /.(. 



Hydrocaulus. — Pinnate stems; main stem is divided into 

 internodes by oblique joints. Each internode carries, as a rule, 

 two pinnte on projecting processes, one at the distal and one 

 at the proximal end. Pinnae alternate ; consist of short inter- 

 nodes with oblique nodes; each internode bears a hydrotheca. 

 Nematophores, one median above and one median below each 

 hydrotheca, and one on the main stem in the axil of the pinna 

 (text-fig. lb,B), and generally one on the front face of the 

 internodes of the main stem at the distal ends in the middle 

 line. The sarcotheca is very rudimentary. The sarcostyle above 

 the hydrotheca is lodged in a depression with a delicate film 

 of perisarc on each side ; below the hydrotheca it lies in a 

 kind of trough of perisarc (figs. B and C) . 



Nematocysts, length 13'4 n, breadth 6'8 ju. 



Diameter, about at the middle of main stem, 0-223 mm. ; 

 thickness of perisarc 18 ju. 



Hydrotheca. — Distal portion curved towards the main 

 stem ; mouth circular, its plane cutting the pinna at an angle 

 of about 30°. Aljcauline wall deeply inflected, forming an 

 intra-thecal ridge which extends half way across the cavity of 

 the cell. This ridge is not completely filled in with solid 

 perisarc as Bale describes in his account of the Australian 

 specimen (0). 



Diameter of mouth, measured in the plane of the long axis 

 of the pinna, 0-222 mm. ; height, measured at right angles to 

 the plane of the mouth, 0-212 mm. 



Hydranth. — About 18 tentacles. 

 • Gonosome. — Not found, but described by Bale for the 

 Australian specimens in the following terms : " Gonangia 



