REPORT ON THE RADIOLARIA. 1749 



The genus Ccelotholus and the two following genera form together the subfamily 

 Ccelotholida, the hollow tubes of which do not communicate by anastomosing branches, 

 and therefore form no lattice-mantle, as in the following subfamily Cceloplegmida. 

 Another important difference between these two subfamilies of Ccelographida is found 

 in the arrangement of the main tubes and their connection with the rhinocanna. In all 

 Coelotholida a pair of divergent frontal styles arise from the truncate oral side of each 

 galea, and are connected with the mouth of the rhinocanna by two lateral convergent 

 paired frenula (right and left) ; whereas the characteristic odd nasal style, which in all 

 Coelaplegmida arises from the sagittal apex of each galea and is connected with the 

 mouth of the rhinocanna by an odd sagittal frenulum, is always wanting. The total 

 number of long verticillate styles, which project over the outer surface of the fork-thicket, 

 is eight in Ccelotholus, whilst it is twelve in Ccelotliauma, and sixteen in Ccelothamnus. 

 The two latter may be derived from Ccelotholus, as the common ancestral genus of this 

 subfamily. 



1. Ccelotholus octonus, n. sp. (PL 122, figs. 1, 2). 



Eight styles of equal length, regularly zig-zag, twice as long (in their free part) as the 

 diameter of the loose fork-thicket. Anchor-pencils gradually tapering from the proximal towards 

 the distal end. Each of the four primary frontal tubes (to the right and left of each valve) is 

 simply forked, and the pectoral (anterior) branch of each tube is so diametrically opposed to the 

 tergal (posterior) tube of the other side, that they form together a double cross. 



Dimensions. Diameter of the whole body 12, of the fork-thicket 2'5. 



Habitat South-Eastern Pacific, Station 300, depth 1375 fathoms. 



2. Ccelotholus cruciatus, n. sp. 



Eight styles of equal length, straight, twice as long (in their free part) as the diameter of the 

 dense fork-thicket. Anchor-pencils of about equal size throughout their whole length. Each of 

 four primary frontal tubes is divided into two equal, widely divergent branches ; the anterior 

 branches of the right side are diametrically opposed to the posterior branches of the left side, so that 

 all eight together form a double cross. 



Dimensions. Diameter of the whole body 20, of the fork-thicket 4'0. 



Habitat. South-Western Pacific (off Sydney), Station 164A, depth 1200 fathoms. 



3. Ccelotholus ancoratus, n. sp. 



Eight styles of different lengths, slightly curved. Anchor-pencils gradually tapering from the 

 proximal to the distal end. Each of the four primary frontal tubes is divided into two divergent 



