82 MADREPORARIA. 



thickness from 1 • 5 to 2 cm. They flatten slightly before forking, and the terminals have 

 short rounded tips about 1 cm. tliick. Though the stems approach closely to one another, they 

 show no tendency to fuse together. The living layer is more than 11 cm. deep. 



The ciilicle.s are superficial except at the extreme tips, where the walls rise as sharp 

 irr^ular zigzags. Elsowliere the wall is not very distinct, the septa starting right from its top 

 edge. These latter, as they start from the wall, are very short, mostly free and slightly 

 knobbed, but not so distinctly as to form a second ring of septal granules round the pali which 

 rise from a lower level. The ring of pali is compact, small, but very conspicuous ; it shows 

 the five principals and a smaller directive palus noticed in the description given by Milne- 

 Edwards (Lcs Cor. iii. p. 175). The columellar tubercle is at a lower level than the pali as 

 the pali are at a lower level than the peripheral portions of the septa. The calicle is well 

 filled with skeletal elements showing no deep open cavities into the interior. Cross sections 

 even near the tips are compact. 



This description is founded upon notes made of the specimen. No. Z 182 e, in the Paris 

 Museum, which I take to be the original type of Lamarck's Porites clavaria. That Lamarck 

 had a specimen and was not referring either to Solander's specimen (see p. 81), nor to Seba's 

 from Curayoa (see p. 30), we gather from the words " mon cabinet " ; certain indications lead 

 me also to think that this is the specimen which Milne-Edwards described, excepting that lie 

 gave the thickness of the stems far too large. 



The locality of the " species " was given by Lamarck as Les mers d'Am^rique et de I'Inde. 

 But the label on this specimen says, " Antilles, coll. Lamarck." The Indian Ocean may have 

 been added to cover corals thought to be specifically identical. At any rate it is clear that 

 this particular specimen is a West Indian form. The review of the Indo-Pacific Porites, 

 given in Vol. V. of this Catalogue, showed no specimen whatever which we could unite with 

 it as even possibly of the same species. See the Historical Introduction, p. 3, on the way this 

 name clavaria has been used. The simple accident of its having been the first specimen 

 describetl, and described as a species in the first systematic work of importance dealing with 

 the corals, has given it a fictitious value, which it is to be hoped is unique in the annals of 

 systematic zoology. Whereas, beyond its description, all that can be said of it is that it 

 belongs to some local form, wliich has apparently not yet been re-discovered. 



68. Porites West Indies x. 3. (P. Americana incerlce sedis tertia.) (PI. XII. fig. 1.) 



[Paris Museum.] 



Syn. Porites furcata Lamarck, Animaux sans Vertebres, ii. (1816) p. 271. 



Porites furcaiu Milne-Edwards and Haime, Ann. Sci. Nat. (3°) xvi. (1851) p. 21, pl. i. figs. 1, 

 la, 15, \c. 



Description. — The corallum rises into clusters of cylindrical stems, which fork or attempt 

 to fork, at distances of from 1 • 5 to 2 cm. and at angles of about 90°. Diverging prongs tend 

 always to bend up into the vertical, and in the centres of dense clusters fusions become 



