106 MADREPOEARIA. 



It seems to approach nearest in the character of its calicles to Pontes West Indies x. 15. 

 But the growth there is not agariciform ; the calicles are larger, and the wall and calicle skeleton 

 seem to have been more uniformly symmetrical with trabecular tips raised over the surface 

 as separate granules. 



It is unfortunate that Duchassaing did not give the exact locality of his specimen. 



95. Porites West Indies x. 30- {P- Americana incertw sedis tricesima.) 



(PI. VI. fig. 9.) 



[" In variis insulis Carabaeis," coll. Duchassaing ; Turin Museum.] 



Syn. Neoporiiei littoralis Duchassaing, Mem. sur les Cor. des Antilles, Suppl. (1864) p. 99. 



Description. — The corallum is encrusting, with wavy or gibbous surface. 



The calicles are shallow, variable in diameter up to 1 • 5 mm. The walls are thick, and 

 built of crisp, much twisted flakes, disposed, for the most part, horizontally, and not very 

 porous. The septa are often ragged points projecting from the edges of the flakes, but some- 

 times long, straight, very thin, and with lateral points, and fairly symmetrically arranged. A 

 thin, flattened, columellar tubercle is usually to be seen. 



This description is again based upon the original text, aided by the magnified photograph 

 of the type in the Turin Museum, kindly supplied by Count Peracca, and reproduced, fig. 9, 

 PI. VI. Unfortunately we do not know from which one of the several islands of the Antilles, 

 referred to by the authors, this particular specimen comes. It lias great interest for us for 

 a comparison with other astraeoid forms of Porites. There is no other showing the flaky 

 character of the skeleton so strikingly developed except abnormally, see P. Bahamas 1, compare 

 also P. Chiadalupe 6. 



96. Porites West Indies x. 31. {P. Americana incertce sedis prima et tricesima.) 



[British Museum.] 



[The specimens are embedded, as fragments of different sizes, in a mass of consolidated 

 raised beach, in which are many fragments of a Madreporid,* great numbers of shells.f 

 echinoid spicules, etc. All the Porites fragments are of the same kind, and their characters 

 may be put into a formal description as follows.] 



Description. — The corallum was branching with stems from 1 • 5 to 2 cm. thick, flattening 

 slightly and forking at acute angles. 



Calicles, 1 • 5 mm. across, conspicuous, polygonal, with the wall sharp when the calicles 

 are slightly sunk, or else raised as a thread when the calicles are obsolete. The septa are 

 clear and well developed, though with interrupted edges, either starting from the edge of the 



• The Madreporid is solidified throughout. 



t Mr. E. A. Smith has kindly given me the following list of recognisable shells, Gastropods — 

 Natica, Cerithium, Columbella, Turbo, Fissurella ; Lamellibranchs — Mytilus, Chlamys and Lucina. 



