Australian Hydroids. 349 



lage7iifera, and, as seen laterally, are not so wide proportionately 

 -at the base, nor are the inter nodes supporting them so turgid. 



Inaba'at description agrees precisely in all particulars of specific 

 value with my specimens, allowance being made for his use of the 

 term '' joint " for the areas between tlie septal ridges as well as 

 -those between the true nodes. Thus when he says that there are 

 .three joints in the stem between two successive branches, it is 

 meant that the internode is divided} into three parts by two septal 

 ridges. It is to be noted, however, that the intermediate inter- 

 nodes of the hydrocladia sometimes have really a secondary node 

 dividing them into two, and this would seem to have been more 

 frequently the case in Inaba's specimen than in my own, since lie 

 refers to it as the normal condition. 



Inaba says : " This species is very small, being less than 10 nun. 

 high, the branches are short, and being all of about the same length 

 this species can easily be distinguished from F. sefacea by its general 

 form. On a closer examination, however, the numl:)er and arrange- 

 ment of the nematophores are found to be exactly the same as in 

 P. setacea. If in P. setacea each joint of the stem were divided into 

 iihree, and each short joint of the branches into two, the arrange- 

 ment would be exactly what we find in the present species. More- 

 over the joints do not appear to be absolutely fixed in this species, 

 being sometimes irregular; in the lower part of the stem particu- 

 larly three joints are frequently united into one. 



*' The more minute differences from P. sttacta are as follows : — 

 'The comparative shortness of the stem, the comparative thickness 

 •of the perisarc, the comparatively small size and greater number 

 of the joints, the comparative shallowness of the bowl-shaped hydro- 

 thecae, and the fact that there are always two on each branch." 



The last-mentioned character is, as might be expected, not in- 

 variable; in some of my specimens the hydrothecae are limited to 

 two on a hydrocladium, in others there are three. 



The gonangia ai-e about .55 mm. in length, the male form has 

 sides straight, so tliat the width is about the same throughout except 

 at the base and the summit; the terminal portion is blunt, directed 

 i;o one side and sometimes slightly narrowed, with an obli(]ue 

 aperture. Female capsules observed were somewhat widened in 

 the middle, and veiy broad at the extremity; these were, however, 

 probably inmiature, as othei- specimens were seen, empty, which 

 were more contracted towards the aperture. Inaba's specimens 

 were without the gonosome 



4\ 



