198 mr. holdsworth on new species of flabellum. [june 24, 



4. Description of Two New Species of Corals belonging 

 TO THE Genus Flabellum. By E. W. H. Holdsworth, 



F.L.S., ETC. 



(Plate XXVIII.) 



1, Flabellum campanulatum. (PI. XXVIII. figs. 1-3.) 



Compressed, campanulate ; borders straight or slightly convex ; 

 without spines. Base usually terminating in a small pedicel, some- 

 times irregularly compressed. Superior margin slightly arched. 

 Cell deep and narrow. Border of lamellae entire, sloping inwards 

 from the apex for about one-third of their length, thence continuing 

 straight to the bottom of the cell. Columella indistinct. Five prin- 

 cipal lamellse in half an inch. Height 14 lines; breadth 16 lines ; 

 proportion of axes 7 : 16. 



Specimens in the British Museum are rather longer in proportion 

 than those in my possession ; but the variation is not very great. 



Hab. Philippines. 



This coral is very neat and symmetrical, and can hardly be con- 

 founded with any other species. 



2. Flabellum nobile. (PI. XXVIII. figs. 4, 5.) 



Much compressed throughout, elongated. Borders rather con- 

 cave, with four or five root-like appendages more or less distant from 

 the base, but closely united throughout their length to the lower 

 half of the coral. These appendages spring from and are continuous 

 with the transverse epithecal ridges which mark the successive 

 periods of increase in the coral, and, although now intimately united 

 to the main stem, are evidently of extraneous growth, corresponding 

 in origin and nature with the ordinary form of spines, but taking a 

 downward direction to increase the basal area. Upper margin of 

 the coral slightly arched. Cell very deep and narrow. Margin of 

 lamellse entire, and gradually curving from apex to base, at which 

 point opposite series of the larger plates almost unite. No colu- 

 mella perceptible. Four principal lamellae in half an inch. 



The two specimens which have furnished the above description 

 are of different ages. The smaller and more perfect example is at- 

 tached to the upper margin of the flat side of the larger one, and has 

 grown in nearly the same vertical direction. It measures 2 inches 

 6 lines in height, and 1 inch 10 lines in greatest breadth. The older 

 example is 2 inches 6 lines in the long diameter, and 1 inch 3 lines 

 in the short. The base of this specimen is imperfect ; so that the 

 original length of the coral cannot be certainly ascertained. 



This species is intermediate between the genera Flabellum and 

 Rhizotrochus, having the usual compressed shape of the former, with 

 a partial development of the radiciform appendages of the latter re- 

 markable genus. The peculiar situation of the smaller specimen is 

 perhaps worthy of notice, as being one in which the supplemental 

 props are especially useful in aiding the attenuated base to support 

 the long and heavy coral. A similar tendency to parasitic growth. 



