54 MADREPOEARIA. 



would be worth investigating whether these Pontes are permanently adapted to this life in 

 sand, or whether they are mere specimens of some other form with a characteristic method of 

 growth altered by having to live on a sandy floor. 



Duchassaing and Michelotti* suggested that this coral was the same as Lamarck's 

 P. furcata ; but see p. 82. 



36. Porites Anguilla 1. (P. Anguillce prima.) (PI. III. fig. 2 ; PI. X. fig. 5.) 

 [Anguilla, coll. Gregory ; British Museum.] 



Description. — The corallum is branching and apparently very small. The stems are 

 about 8 mm. thick, and either round or slightly flattened. They appear to fork at distances 

 of 8 to 10 mm. apart. The forking is irregular, one prong often aborted and the other 

 (? accidentally) somewhat twisted. The flattened ends are often with only one lateral out- 

 growth, making the tips irregularly hammer-headed. The living layer is 2 cm. deep. 



The caUcles are mostly very minute, 1 mm. the largest, and much less ; they show great 

 irregularities and variations of structure. The walls are raised, and are stout and irregular, 

 consisting of thick wall, or septal granules, crowded too closely to show much trace of any zigzag 

 arrrangement of the concentric elements. In the larger caHcles, the complete, septal formula 

 can be made out ; the septa meet in coarse nodes which rise as pali. In the smaller calicles, 

 their numbers may be greatly reduced, and the ring of pali may be united with the walls by 

 quite irregular septal strands. The interseptal loculi are clear and deep in the younger 

 calicles, and the whole skeleton is more open, its elements being thinner, but in the older 

 and shallower calicles the elements are thick and coarse, and the interseptal loculi much 

 shallower and less marked. In these latter, the columellar tangle is frequently a solid plate, 

 elsewhere a deep open fossa occurs in the place of the central tubercle. 



In the section, the skeletal elements are seen to be very irregularly arranged, and very 

 thick and coarse especially round the periphery. The axial, streaming reticulum is stout, 

 but of a somewhat finer texture. 



Two small fragments were examined and figured : one, the larger, appeared as if it had 

 been standing erect when collected, the other (a) as if it had been loose, and lying on its 

 side, from which side two finger-like up-growths have started. These up-growths may perhaps 

 represent early stages in the growth of the colony, and illustrate its habitual method of rising 

 into branching forms. The larger of these finger-shaped processes is 12 mm. long, and 6 mm. 

 thickest diameter, the smaller 8 mm. and 4 mm. Both these up-growths consist entirely of a 

 close reticulum such as that which formed the axis of the larger specimen (since accidentally 

 mislaid), and the tips of its forkings. 



The calicles are difficult to describe owing to their small sizes, and the irregularities in 

 the thickness of the skeletal elements, which are generally smooth. In this latter fact, as well 

 as in the sizes of the calicles, and also in the growth-form, this coral differs conspicuously from 

 P. Porto Rico 2, which is another of the known minute West Indian forms. 



• M6m. sur les Cor. des Antilles, Suppl. (1864) p. 95. 



