320 ERNEST WARREN. 



Gonosome. — Both male and female gonangia may occur on 

 the same stem. 



Male gonangia ovate, spring from the internode just on one 

 side of the mesial nematophore. The gonangium has a short 

 jointed stalk or peduncle Avhich is provided with two lateral 

 nematophores (text-fig. 14, C, ^). 



The average size is 0*384 mm. in length and 0"253 mm. in 

 breadth. 



In the same figure a larger gonangium is seen, which is 

 female. It would appear that the blastostyle has produced 

 a second gonophore, since the operculum has opened, and a 

 large, round, terminal aperture is present, through which, it is 

 assumed, the products of the first gonophore have escaped. 



Systematic Position. — This hydroid closely resembles 

 Antennella gracilis Alhnan^ and P. catharina Johnston, 

 and especially the hydroid regarded by Hincks as a stemless 

 variety of catharina. It agrees in having male and female 

 gonangia on the same stem. It is, however, markedly different 

 from c a t h a r i n a in the extreme obliquity of the nodes. With- 

 out an examination of a number of specimens of catharina 

 from various localities, it is not possible to judge whether such 

 a character should, or should not, be regarded as of specific 

 value. 



(24) Plumularia spinulosa Bale. 



Plumulabia spinulosa. Bale. ' Cat. of the Australian Hydroid 



Zoophytes." 1884, p. 139. 



This minute species has been found on one or two occasions 

 at Park Rynie. It grows on sea-weeds or larger hydroids. 

 About one-sixth of an inch in height. 



Trophosome. — Hydrorhiza reticular; numerous pegs of 

 perisarc project into the cavity from the vertical sides as in 

 P a s y t h e a . 



' Nutting, C. C. 'American Hydroids." Part I. " PInnmlarida?.' 1900 



p. 77. 



