ióo 



of the ovicell, ooeciostome and cancelli are, however, much as in other specimens which are 

 believed to belong to the present species. 



M easuremen ts , in a: — 



Greatest diameter of the largest colony, 56S. B. 3 , 8,500; 



Greatest diameter of the colony, fig. 11, 4,600; 



Greatest diameter of the colony, fig. 10, 2,900; 



Greatest diameter of the colony, fig. 9, 3,200; 



Length of longest peristome, fig. 8, 1,000 ; 



Greatest diameter of ovicell, fig: 1 1 , 1,850; 



Length of longest zooecial series, fig. 11, 1,200; 



Width of zooecial series, fig. 11, 80 ; 



Average diameter of openings of larger cancelli, fig. 10, 130; 



Diameter of ooeciopore, fig. 8, 75. 



The determination of the species of Lichenopora is admittedly very difficult ; and it is 

 probable that the present species has been described under several specific names. Forms like 

 the colony shown in fig. 8 have a considerable resemblance to L. radiata, originally described 

 by Audouin l ) as Melobesia radiata, on the basis of Savigny's excellent figures -). In these 

 figures the rays are represented as being uniserial, with the central zooecia greatly elevated, 

 and longer than those which occur nearer the margin. The existence of an ovicell or ovicells 

 is clearly indicated in Savigny's fig. 3*; but it appears from the figures that the cancelli are 

 smaller than in L. novae-zelandiae, from which it is probably distinct. 



Mr Waters 3 ) has figured the ovicell of a form referred by him to L. novae-zelandiae, 

 which differs greatly from the ovicells described in the present Report. A central smooth region, 

 not covered by cancelli, is represented as being surrounded by a sharply marked calcareous 

 ridge. This has some resemblance to the ovicells of specimens from Ceylon described by Busk 

 as Discoporella holdsworthii (see below). 



L. novae-zelandiae has been recorded from the Azores by Jullien and Calvet *) but in 

 the absence of figures it is perhaps permissible to doubt the correctness of the reference. 



In his paper on the ovicells of Lichenoporae, Waters 5 ) describes an ovicell which 

 corresponds closely with those found in the l Siboga' specimens; but he refers the specimens 

 to L. victoriensis, a new name for L. reticulata MacGillivray, preoccupied. It appears to me 

 probable that this is really L. novae-zelandiae. 



The ovicell figured by Waters g ), in the same paper, as that of L. echinata MacG. 

 develops in the same manner as that represented in my own fig. 6; but MacGillivray's species, 



1) Audouin, V., "Explication", "Pol.", 1826, p. 235; Ed. 2, 182S, p. 60. The specimen (Biït. Mus. 90.3.24.54) from Torres 

 Straits referred by Mr Kirki-atrick (1S90 2 , p. 612) to Lichenopora radiata has strongly marked radial ridges composed of 2 — 3 series of 

 connate zooecia, and has much resemblance to Radiopora cristata Busk (1S75, p. 35). 



2) SAVIGNY, J. C, «Descr. Egypte", PI. VI, figs 3"— 3*. 



3) Waters, A. W., 1887, «Bry. N. S. Wales", III, Ann. Mag. Nat. Hist. (5) XX, p. 261, PI. VII, fig. 8. 



4) Jullien, J., and Calvet, L., 1903, "Bry.", Rés. Camp. Prince de Monaco, XXIII. p. 164. 



5) Waters, A. W., 1889, t. cit., p. 2S4, PI. XV, fig. 4. 



6) Ibid., 1889, t. cit., p. 282. PI. XV, fig. 6. 



160 



