HYDROZOA BITCH I E. 



841 



Dimensions. — 



Organs. 



Present specimens. 



Bale's Figures. 



Stem, diameter 



Distance between hydrothecse 



Hydrotheca, length adnate 



,, ,, free 



0-73-1 -47 mm. 

 0-18-0-21 ,, 

 0-29-0-41 ,, 

 0-360-42 „ 

 0-17 mm. 



0-47-0-60 mm. 

 25 mm. 

 0-37-0-40 mm. 

 0-25-0-32 „ 



„ diameter at mouth 



0-17-0-20 „ 



Locality. — Station 57, off Wata Mooli, three and a half to four 

 miles off shore ; depth, 59 to 54 fathoms ; bottom, mud ; 22nd 

 March, 1898. 



Sertiilarella longitheca has hitherto been found only at Port 

 Denison (Bale, 1888), and Port Phillip (Bale, 1894), 



SERTULARELLA LONGITHECA, Bale, 



var. ROBUST A, var. nov. 



(Plate Ixxxviii., fig. 8 ) 



Stations 36, 44, and 48. 



Specimens from two Stations appear to belong to a variety of 

 the above species. They occur in short monosiphonic coloninsj 

 only about 3 cm. in height, lax in <.'rowth, with rare and irregular 

 branches which spring, with a long internode, from directly 

 beneath a hydrotheca, and which are similar to the longer 

 *'stem." In the older portions of the colonies, owing to the 

 great thickness of the perisai-c, the nodes become obscured, 

 although a slight constriction immediately distal to a hydrotheca 

 generally indicates their position. The internodes do not lie in 

 a straight line, as in Bale's figure (1888, pi. xvi., fig. 5), but are 

 zig-zag, bending to one side and the other in gentle curves which 

 follow the inner lines of the hydrothecse. 



The hydrothecse lie towards the distal ends of the internodes, 

 and are remarkable for their great depth and for the length of 

 the adnate portion. They are not quite tubular, as in the typical 

 form, but reach a maximum diameter at the point where they 

 become free, tapering slightly downwards until they end iu a 

 rounded base, and less markedly towards the mouth. Many 

 show indications of a faint rugosity on the free adcauline wall. 

 There is some variation in the proportion of the adnate part of 

 the hydrotheca. In no case has so small a portion as a third 

 been observed, although such occurs in the typical form; for the 



