BERMUDAN PORITES. 79 



64. Porites Bermuda 2. {P- Bermuda; secunda.) (PI. IV. fig. 8 ; PL XII. fig. 3.) 

 [Bermuda, coll. ' Challenger' ; British Museum.] 

 Syn. Porites clavaria Quelch (?to» Lamarck), Chall. Rep. xvi. (1886) p. 179. 



Description.— The corallum rises from a dead tangle of previous growth, over which it 

 sends out creeping edges. The basal stems are short and very thick, {ca. 3 cm.) and forking 

 rapidly about every 2 to 2 • 5 cm., the rounded terminals are about 1 • 2 cm. thick. The living 

 layer may extend some 9 cm. from the terminals to the basal encrustation of the dead tangle. 



The calicles are only faintly pitted, and appear in the bleached coral as delicate long- 

 rayed stars, somewhat smaller (1-25 to 1-50 mm.) on the terminals than they are on the basal 

 stems (1 • 5 to 2 • 00 mm.). The walls show variations in thickness, they are for the most part 

 thin zigzag lines, rugged and nodulated as are the septa, and sometimes incomplete, but here 

 and there this is replaced by a fine foaming network with round pores or meshes and smooth 

 threads. The septa project at different levels as rugged, very echinulate rods which soon join 

 a large, close, columellar tangle ; small rugged pali arise and a still more obscure central tubercle. 

 The typical formulae can be traced both in septa and pali though somewhat obscured by the 

 roughness of the skeletal elements. 



The section shows a very open, subrectangular network of trabecular and horizontal 

 elements, with large rounded meshes ; the polyps extended some 3 mm. into the coral, and 

 tabula are pronounced. 



This coral has no claim that I can see to be identified with the West Indian form called 

 by Lamarck " clavaria." It is obvious from Mr. Quelch's text that he was following the lead 

 of Pourtales, and was uncertain whether to call it clavaria ovfiircata. Lamarck's clavaria, see 

 p. 81, branched more freely, and at the terminals had thin raised walls, and pali sufficiently 

 well developed as to show a distinction between the five principal pali and the one on the 

 dorsal directive. 



There is one large specimen showing the growth of the stock upon a fragment of a dead 

 tangle, and a box of smaller pieces. 



a. Zool. Dept. 86. 12. 9. 310. 



b. Four fragments. „ 92. 10. 16. 19. 



6.5. Porites Bermuda 3. (P. Bermuda' tertia.) (PI. IV. fig. 9.) 



[Bermuda, coll. A. E. Shipley ; Cambridge University Museum.] 



Description.— The corallum is branching ; the short, cyUnclrical basal stems are smooth 

 and swollen, slightly over 2 cm. thick, and forking dichotomously at wide angles about every 

 2 cm. The small, rounded terminals flatten a little before divitUng, and are a little less than 

 1 • 50 cm. thick. 



