98 KEC'Oi;i)S OF THE AUSTI;AI,IAX .MLSliL'M. 



The ocelli occur on the exumbiellar surface ai the bases of the 

 tentacles ; they are bi-ight red in colour and are surrounded by a circlet 

 of white pigmeiit-f^ranules. A vertical section sliows the ocelli, which 

 project slightly on the surface, to be composed of densely packed pigment- 

 granules; a lens is not present. 



The tentacles are only very slightly pigmented. Granules of white 

 pigment are grouped in little heaps near the proximal end of tlie main 

 stem of the tentacle. A row of similar granules extends along the main 

 stem and is continued down the entire length of the lowei- branch ; tliese 

 wliite granules are usually absent from the upper biauch of the tentacle. 



Fixed material is somewhat different in appearance owing to the 

 cream-coloured pattern on the exumbrellar surface, and the white granules 

 of the tentacles disappearing in the preservative. 



The tentacles. — The tentacles are very variable in number, ranging From 

 six in the youngest individual to about thirty-one in the largest. In adult 

 specimens the arrangement of the tentacles bears no relation to the radial 

 canals, but in the youngest specimen obtained there are six well-developed 

 tentacles arising from the circular canal opposite the ends of the i-adial 

 canals, Avhich in this particular speciiuen are six in number. The 

 development of the subsequent tentacles is apparently quite irregular as 

 there are two young specimens in the collection with ten and thirteen 

 tentacles respectiveh*. The growth of a tentacle is fairly rapid, fully 

 formed tentacles being produced on a,n individual ke})t under observation, 

 at the rate of one in every three or four days. 



Each tentacle consists of a main stem which is divided at its distal 

 end into two branches, a shoit u[)per and a longer lower branch. In living 

 and fully expanded adult specimens the lowei" biancli is a little longer 

 than the upper one. The main stem of the tentacle is slightly shorter 

 than the upper biauch. In young specimens the lowei- branch of the 

 tentacle is markedly longer than the upper ; and in the youngest individlial 

 obtained the lower branch in the fully expanded condition was twice as 

 long as the up[)er branch of the tentacle. In mature specimens, however, 

 the branches become moie equal in length, so that in adult forms the 

 lower is only slightly longer than the upper bi-anch. In ('. r<iiii'H.<r, 

 according to Gilchrist, " the upper branch is about three times the length 

 of the lower branch in the living and fully expanded condition." This 

 difference between the lengths of the upper and lowei' bi'anches of the 

 tentacles serves at once to distinguish ('. Intsiri-lli from the Cape species. 



On the upper biaiudi of the tentacle are borne the neniatocyst-clusters, 

 which are aboi-al and oral in positioji, their arrangement being very similar 

 to that described by (lilchrist in the case of ('. (•(ijwiise. Owing to the 

 shortness of the uppei" bi'anch of the tentacle in ( '. /nis-icflli, the neniatocyst- 

 clusters ai'e more concentrated in theii' i-elative positions than the\' ai'e in 

 the C'ajte s[)ecies. 



There is a knob-like terminal cluslei' of nemalocysts, wliicli is fol lowed 

 by a second cluster on the upper or aboral side of llie tentacle. This 

 second cluster is separated fiom the teiniinal cluster by a slioit interval ; 

 in young individuals the cluster is completely abi^tral in position, but as 



