A COLLECTION OF HYDBOIDS. 289 



tentacles; and it would appear probable that both Asyn- 

 coryne and Cladocoryne are to be regarded as modifica- 

 tions of the Coryne type. 



As the generic name implies the present hydroid is especi- 

 ally associated with Syncoryne^ since the reproductive 

 bodies are, with great probability, free-swimming medusae. 

 The general shape of the hydranth also recalls Syncoryne, 

 although the habit of growth of the colony is simpler. 



(10) Coryne piisilla Gi'irtner. 



Coryne pusilla G'irtuer. Pallas, 'Spieil Zool,' fasc. x, p. 40; Allman, 



G. J., ' A Monograph of the Gymno- 

 blastic Hjdroids,' 1872. p. 266. 



The identification of the Natal hydroid with Gartner^s 

 pusilla is not made with any certainty; but without a 

 detailed acquaintance of the variability and general growth- 

 forms exhibited by pusilla it appears advisable to refer it to 

 this species, as no obvious specific difference has been deter- 

 mined. 



The hydroid appears to be very variable in size. There is 

 a dwarf variety, about one quarter of an inch in height, which 

 stretches over large areas of seaweed (text-fig. 4 B) exposed 

 to the force of the waves, while in more sheltered places it 

 grows to nearly double the size (A). 



Tkophosome. — Hydrorhiza forms an irregular loose mesh- 

 work on weeds or rocks. The perisarc is smooth, without 

 annulations. 



Diameter 0'162 nnn., thickness of perisarc 2t)"8 /j. There is 

 no marked difference in the size of the hydrorhiza in the 

 dAvarf and large varieties. 



Hydrocaulus. — Straggling and irregularly branched; 

 serpentine, blind-ending branches occur. The annulation o 

 the perisarc is variable and irregular; it is generally most 

 distinct for some distance below the hydranth ; there are 

 about 20 ring's to the millimetre. 



