THE RESULTS of DEEP-SEA INVESTIGATION in the 

 TASMAN SEA. 



I.— THE EXPEDITION of H.M.C.S. "MINER." 



2. The Colonial Radiolariaof the Tasman Sea. 

 By Prof. W. A. Haswell, M.A., D.Sc, F.R.S. 



(Plate liii.). 



The colonial Radiolaria collected during the two-days cruise of 

 H.M.C.S. "Miner" in June, 1906, were mostly obtained at a 

 distance of over fifty miles off the coast. Here, probably on 

 account of the strong southward-flowing current, with a surface 

 temperatux'e of 65° C, surface life was very abundant and varied. 

 Owing to the unfavourable weather it was impossible to do more 

 than drag the tow-net for a time within a few feet of the surface, 

 and the specimens obtained had to be somewhat summarily dis- 

 posed of. The fixing solution employed — a copper sulphate and 

 corrosive sublimate combination — though very efficient as regai'ds 

 most of the surface organisms, was not entirely successful in the 

 case of the colonial Radiolaria, having had, apparently, a soften- 

 ing effect on the jelly which led to the disintegration of most of 

 the colonies. Fragmentaiy though the specimens are, the indi- 

 vidual zooids prove to be remarkably well preserved. To com- 

 plete the observations here recorded, however, the study of further 

 material preserved in other ways, and of living specimens will be 

 necessary, and what follows can only be regarded as a preliminary 

 account of the colonial Radiolaria of this region. 



The points of more general interest, to which attention is 

 directed, are : (1) The observation in a species of CoVozotim, as 

 well as in Belonozouni aflatiticum and lihaphidozouni pandora 

 of bodies which appear to be zooids that have undergone conver- 

 sion into masses of microspores ; (2) The observation in Collo- 

 zoum arcuatum, n. sp., of a special phase in the life-history 

 of the Xanthellcc. 



It is somewhat remarkable that so few Radiolaria have been 

 recorded from the Tasman Sea. Of the colonial forms I find 

 record of only three species having been found in that region, 

 viz., Sphaerozoiim octoceras, Haeckel, *S'. australe, Haeckel, and 

 Collosphaerafragilis, Haeckel. The reason for this is, doubtless, 

 that so little plankton-net collecting has been done in the open 

 sea. The Radiolaria, and more particularly the colonial forms, do 



