HADIOLARIA OF THE TASMAN SEA^ — HASWELL. 279 



Belonozoum atlanticum, Haeckel. 



Belonozoum atlanticum, Haeckel, The Radiolaiia, Chall. 

 Rep., Zool. xviii., 1887, p. 40. 



To this species I refer several specimens which resemble one 

 another and agree with Haeckel's description and figure in the 

 character of the spicules. The entire colonies are more or less 

 elongated and cylindrical. At least two distinct forms or phases 

 are represented. In one the zooids are comparatively large (from 

 0-1 to 0"2 mm.), and each contains from one to three nuclei : there 

 are many Xanthelka in the layer (pseudopodial matrix) innnedi- 

 ately surrounding the capsule. In the other form the largest of 

 the zooids is about O'l mm. There are about half-a-dozen small 

 nuclei in each, and there are very few Algte. 



All the specimens contained the sharply-defined granular 

 masses described as occurring in CoUozoutn alpha. These vary a 

 good deal in size, but are, for the most part', considerably smaller 

 than the zooids. In a complete colony there are about a dozen of 

 them, all placed superficially. 



The " Challenger " locality for B. atlanticum is the tropical 

 Atlantic. 



Belonozoum hilli, sp. nov. 



This species forms spherical colonies. The spicules are all 

 simple and unbranched, but are of two kinds. Those of one kind 

 are extremely slender, elongated and curved, usually as long as, 

 or somewhat longer than, the diameter of the capsules (0-15 aim.), 

 and quite devoid of spines. The other set, which are much fewer, 

 are shorter, usually straight, and beset with spines throughout 

 their length — the spines being longest towards the ends. Be- 

 tween these two kinds are a number of intermediate forms — long, 

 slender, usually curved, and spinose only, or chiefiy, at the ends. 



The capsules are large, about 0-15 — 0-24 mm. The outer por- 

 tion of the inti'a-capsular protoplasm is granular and pigmented. 

 In the interior are several — 3-6 — oil-globules of considerable size, 

 and a number of nuclei, most of which are grouped towards the 

 centre. Embedded in the pseudopodial matrix, which has a reti- 

 culate structure, are a numlier of Algpe. 



Brandt states that young specimens of Sphn-i'ozoimi may have 

 needle-like spicules only. But, as he states that all the young 

 stages of the species of that genus which he had closely studied 

 were more or less elongated — cylindrical oi' sausage-shaped, I 

 think it is most probable that the species above described is to be 

 looked upon as a Belvnozoum. 



