198 CEYLON PEARL OYSTER REPORT. 



factory) figs. 26, 30, 31 and the Oeylonese specimens, while the latter can certainly 

 he included in the amended definition of F. rubrum given by Gardiner on p. 28. 

 It is further stated that F. va/riabile, Semper, is connected with F. rubrum by 

 individuals, Kemper's species being identified by Moseley with F. stokesi, 

 M. Edwards and H., which in turn is identical with F. oweni, aculeatum, spinosum, 

 debile, sumatrense and candeanum. I must take leave to doubt whether these 

 identifications are correct. That F. variabile, Semper, is identical with Flabellum 

 (Turbinolia) rubrum, Qrov and Gaimard, I have no doubt. The characters of the 

 corallum are similar and a comparison of Semper's figure of the expanded polyps 

 (49. plate xviii., fig. 1) of F. variabile with Quoy and Gaimard's figure of 

 F. rubrum (46, plate xiv., figs. 5 to 9) show a very close correspondence in the 

 coloration of the living animal ; in both there are the same six alternating radial 

 bands of deeper red and lighter red or yellow. On the other hand, F. irregulare, as 

 described by Semper, is red with as many radial white lines as there are principal 

 septa. The colour, no doubt, is variable to some degree, but it must be taken into 

 account, and what I wish to point out here is, that Semper is the only author who 

 has paid special attention to the colour of the living polyp ; that he had at least as 

 many specimens for comparison as Gardiner ; that he found a constant colour- 

 difference between his F. variabile and F. irregulare, and that the colour of the 

 former, and not that of the latter, corresponds to Quoy and Gaimard's figure of 

 F. rubrum. It follows, therefore, that F. variabile = F. rubrum, and, as Semper 

 showed beyond all cavil, F. stokesi, oweni, aculeatum, spinosum, debile and 

 sumatrense, all M. Edw. and H., are synonyms of F. variabile. 



The Oeylonese specimen, which I identify with F. irregulare, Semper, agrees very 

 closely with F. crassum, M. Edw. and H., especially in the characters of the septa, 

 which are notched near their insertion on the wall (38, plate viii., fig. 8a), and 

 have thickened and rugose internal borders. Semper observes that the two species 

 are very closely allied, differing chiefly in the height of the corallum. There can be 

 no doubt that they are identical ; the specific name crassum has the priority, and I 

 therefore identify the Oeylonese specimen above described as F. crassum, M. Edw. 

 and H. 



Flabellum rubrum, Q. and G. Plate I, fig. 4. 



There are three other specimens of Flabellum in Professor Herdman's collection : 

 a and b (locality not recorded), and c from deep water near Galle. These are all 

 truncate forms with a fairly large basal scar ; their measurements correspond closely, 

 their calices are elliptical, their calicular fossa? wider, and the septa are thinner, and 

 their inner margins less vertical than those of F. crassum, and the spines on the 

 surfaces of the septa are longer, further apart, and definitely arranged along radial 

 thickenings of the septa. Their walls are thinner than in F. crassum, the costse are 

 of ecpial size and very slightly developed, and the corallum is not constricted at 



