858 " THETIS " SCIENTIFIC RESULTS. 



rhizoidal tubes at base. The characters agree in detail with 

 Bale's descriptions except that the few branchlets present show 

 no sign of incurving towards each other at the tips. 



As the following measurements show, there is a considerable 

 amount of variation in the length of the free portion of the 

 mesial sarcothecse, these structures in general presenting a series 

 which gradually increases in length from the proximal portion of 

 a hydroclade towards its tip. In one case there was no terminal 

 perforation in the mesial sarcotheca of a proximal hydrotheca. 

 No gonosome was observed. 



Dimensions. — 



Hydroclade-bearing internode, length 074 0-78 mnn, 



,, ,, diameter 0-49-0-56 „ 



Hydroclade internode, length 0-33-0-36 ,, 



,, ,, diameter 0-21-0"25 ,, 



Hydrotheca, depth*" 0-21 „ 



hreadth^s 0-18-0-20 „ 



,, length of free portion of mesial sar- 

 cotheca 0-05-0-13 „ 



Localities. — Station 44, off Coogee, five to six miles from shore ; 

 depth, 49 to 50 fathoms ; bottom, tine sand ; 15th March, 1898 ; 

 one unbranched colony, 9 cm. high. Station 48, off WoUongong, 

 seven to eight miles from shore ; depth, 55 to 56 fathoms ; 

 bottom, sand and mud to rock; 18th March, 1898; two frag- 

 anentary branched colonies. Southern coast New South Wales ; 

 two colonies. 



The specimens from Station 48 were at first sight indistin- 

 guishable froni a colony of Halicornaria thetidis, along with 

 which they were growing. 



HALICORNARIA PROLIFERA {Bale). 



(Plate Ixxxv., figs. 2, 3.) 



Aglaophenia proli^era, Bale, Jouru. Micro. Soc. Vict., ii., 1882, 

 p. 34, pi. xiv., fig. 5. 



Halicornaria proli/eo-a, Bale, Cat. Austr. Hydroid Zoophytes, 

 1884, p. 183, pi. xiv., fig. 1, pi. xvi., fig. 10. 



I regard as belonging to a variety of Halicornaria prolifera 

 three monosiphonic, unbranched, simply pinnate colonies, the 

 largest 17 cm. in height, which were associated with Halicornaria 

 furcata. In the following points they differ from the specimens 



*''' Measured from aperture to base along long axis of hydrotheca. 

 *8 At right angles to depth. 



