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marked differences between them. One of them consists of branches of the type described in 

 the other specimen, except that the meshes are more irregular in size. The other has branches 

 which are rather more divergent and less parallel. In this specimen the zooecia agree with 

 those of the colony from Stat. 119; but in the other piece, which has parallel branches, the 

 zooecia exhibit the curious modification which is illustrated by figs 6 and 9. The median part 

 of the wall of the peristome is here prolonged into a flat, shield-like portion which almost or 

 entirely conceals the orifice, in a frontal view of the branch. In a side view (fig. 9) it is seen 

 that the terminal portion of the peristome comes off at right angles from the shield-like part, 

 which is prolonged beyond it. The same specimen has the lateral edges of the basal wall of 

 its branches distinctly serrate (figs 6, 9, 10), the projecting parts being transverse and joining 

 the rest of the branch at right angles distally, and sloping gradually in the proximal direction 

 into the side of the branch. The occurrence of septal lines outlining these serrated portions 

 (fig. 9) indicates that the parts in question are really kenozooecia and are thus outer zooecia 

 which develop no orifices. It may be concluded that the zooecial series consist of two zooecia, 

 of which the median one possesses an orifice and is a complete zooecium, while the outer one is 

 reduced to a kenozooecium. This serrated condition has not been found in the other specimens, 

 in which, however, the lateral parts of the branches appear to be similarly constituted of 

 kenozooecia, which do not project in the way just described. Since the transverse connexions 

 between the branches are produced from these lateral regions, it may be concluded that some 

 of the lateral zooecia have been modified into kenozooecia which unite in bundies to form the 

 cross-connexions. These facts seem to indicate that the present species is comparable with other 

 species of Tubulipora in which several zooecia unite laterally to form the alternating series. 

 The complete zooecia always have the outer parts of the distal portion flattened. 



The ovicells are "simple", in the sense that they are dilatations which do not bifurcate 

 with the branch. Their form is shown in fig. 7, where it will be seen that the ovicell, although 

 much infiated, is not much wider than the branch. The inflated part of the ovicell commences 

 abruptly at its proximal end. The ovicell extends round the zooecia which occur in its region, 

 on their outer sides; and an angular ridge is formed at the side of it, distally to each complete 

 zooecium, and sometimes elsewhere. In all the specimens in which an ooeciostome occurs, this 

 structure is found at the distal end of the ovicell, on one side. It appears as a wide tube, the 

 ooeciopore of which looks frontally (see the right side of the distal end of the ovicell in fig. 7) ; 

 but I am not sure that the ooeciostome is fully formed in any of the ovicells present. 



M e a s u r e m e n t s , in u. : — 



Width of branches, between the cross-connexions, fig. 8, 340 — 410 ; 



Diameter of cross-connexions, fig. 8, 190 — 210; 



Length of infiated part of ovicell, fig. 7, 1,700 ; 



Greatest width of proximal part of ovicell, fig. 7, 635; 



Greatest diameter of orifices, up to 175; 



Diameter of zooecia, fig. 6, 150. 



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