834 MR. .T. IMTOIIIE OX nVDROIDS [^f='} -^> 



the inv:iri;il)lt' jiosition they nssume, seem to show that there is 

 lit) inoval>ility in any of the metliau saicotheccB. 



The c()k)nies are mature, male fjonan^na arisiii<T from the stem 

 at the proximo-lateral portion of a hydrotheca, on the side other 

 than that from which a hydroclade springs. They are club- 

 sl)aj)ed in lateral as{)ect, resembling the gonangia of /'. geminata 

 Allman, and are furnished with a stalk consisting of two short 

 internodes, each of which has a thick adcatdine wall, from which, 

 in the second, a diminutive chitinous ledge })rojects inwards. 

 Although a nematoi)liore usually occurs on each side of the 

 gonangium, occasionally only one side is furnished with an 

 individual. 



Dimensions : — 



Stem internode, length 0"35-0-43 mm. 



„ ,, diameter 0-07-0-11 mm. 



Hydroclade, length up to 2 mm . 



„ thecate internodes, length* ()-2r)-0'l:U mm. 



„ intermediate „ ,, 0-18-0'21 mm. 



Hydrotheca, dept,h 0-21-0-22 mm. 



,, diameter at mouth 0-17-0-18 nun. 



Gonangium (male), length 0-36-0--i2 mm, 



,, ,, greatest diameter in lateral 



aspect 0'17-0'18 mm. 



Locality. Growing on a sponge from the llecf, Flying Fish 

 Cove. 



The only previous Indian Ocean i-ecord is that of MissThornely, 

 fiom Gulf of Manaar. 



Plumularia setacea Linn. (?). 



1758. Sertnlaria setacea Linnteus, Syst. Nat. p. 813. 



Many small colonies apparently belonging to this widely-dis- 

 tributed species, and averaging 15 mm. in height, Avere found 

 growing on a sponge. As it seems impossible to separate this 

 species from P. striclocarpa Pictet by characters of the trophosome 

 alone, and as the gonosome is not pi'esent on any of these speci- 

 mens. I refer them doubtfully, by courtesy, to the older, and cos- 

 mopolitan s[)ecies, until the discovery of the gonothecte shall fix 

 their identity. For guidance 1 ajipend dimensions of parts. 



8tem internode, length 31-0-40 mm. 



,, „ diameter 0-051-0-159 mm. 



Hydroclade, length 2 3 nun. 



Uydrothecate internode, length 0"32-<)'3() nun. 



Intermediate ,, ,, 0-17-O-2r) mm. 



Hydrotheca, depth OOyO mm. 



,, diameter at mouth O-096-O-1O5 mm. 



L()C<diti/. Reef and piles of the pier, Flying-Fish Cove. 



' .Mfiismril fioni ( xlrciiK' luiiiits. 



