102 



this connexion, that in the original account of C. elongata, the only complete internode figured 

 by Milne Edwards has 20 zooecia. The specimens described by that author are believed to 

 have come from the Red Sea. 



The specimen from Lifu recorded by Miss Philipps as C. denticulata has no ovicell, but 

 in other respects appears to agree with the present form. 



The Japanese specimen has no ovicells, but is referred with some doubt to the present 

 species. C. nigrijuncta was described by Ortmann from Japan-, and, as its name indicates, it 

 possesses black joints. 



The 'Challenger' specimen, from off Fiji, has no ovicells, but in other respects agrees 

 closely with the 'Siboga' material. The internodes have a pronounced sigmoid curvature, and 

 some of them have two branches and an even number of zooecia, in one case rising as high as 

 36. The joints are brown ; but it may be noted that this specimen differs from others recorded 

 in coming from much deeper water (1450 fathoms). 



The specimens from the Red Sea determined by Mr Hincks as C. elongata are mere 

 frao-ments; and although the determination appears to be probable, I cannot be confident 

 about it. 



I have not examined specimens from the Sudanese Red Sea; but there can be little 

 doubt that the form recorded by Mr Waters as C. denticulata is the present species. I have 

 found the "thin oval spot" recorded by that author in Canada balsam preparations ('Siboga', 

 N° 253. A. 2 ; Queensland). It occurs, in the position shown by Waters in PI. XXV, fig. 11, on 

 the frontal side of the zooecium, just where the peristome turns frontally to become free. I have 

 not been able to make out its significance, but it is possible that it may be a result of the 

 sudden bending of the wall of the zooecium at this point. The "narrow tube from the distal 

 base of the ovicell" described by Waters (p. 233, PI. XXIV, figs 1, 2) is clearly the modified 

 peristome of the zooecium which next succeeds the ovicell, as described above, p. 100, and 

 shown in fig. 1 . 



In his most recent paper (19 14) Waters records both C. denticulata and C. elongata 

 from the neighbourhood of Zanzibar; and both are said to have the "small mark" at the base 

 of the peristome. C. elongata is described as having only one branch on each internode, 

 springing from the 6 th to the io th zooecium of one side. I have shown above that the number 

 of branches is variable in the 'Siboga' material; and I think it not improbable that the two 

 forms recorded by Waters really belong to one species. This author states that ovicells are 

 not known in C. elongata. 



Measuremen ts, in ,u, of 'Siboga' specimens: — 



Diameter of orifices, 50 — 75 ; 



From centre of orifice to centre of the next orifice, on the same side of the branch, 275 ; 



Width of branch, 250 — 300 ; 



Length of ovicell, measured from the distal end of the preceding zooecium, on the same side 



of the branch, 500 — 750; 

 Width of ovicell, 500 — 575. 



