WEST INDIAN ISLANDS POKITES. 31 



If we are justified in assuming that this figure of Seba's is a good representation of the 

 specimen, and that shouhl go ahnost without saying, considering tlie known accuracy of his 

 illustrations of other objects, we have in this coral a method of growth which deserves 

 attention. It is difficult to say exactly what was the form of the explanate Ijase from which 

 the stems seem to have started, almost as if they were out-growths of its edges. Un- 

 fortunately, Dr. Wayland Vaughan was unable to find any form at Curajoa which at all 

 closely resembled it. It is true that he found a branching Pontes, but with a growth-form so 

 entirely different that, following the principles here laid down, we must consider it as a differ- 

 ent coral. For the description of Dr. Vaughan's coral, see P. Ciira^oa 2. In growth-ibrm it 

 shows the very opposite extreme to Seba's coral, viz. a close clustering, while the forking of 

 the older form is such as to make close clustering impossible. As noted by Dr. Vaughan, 

 branching forms more nearly like that of Seba's coral occur in the Florida reefs. In this 

 Catalogue we have been able to record a few instances of this straggling type (P. Barbados 

 3, PI. IX., fig. 5 ; P. Antigua 3, PI. X., fig. 7 ; P. Belize 1, PI. IX., fig. 1) ; and one from 

 the Florida reefs (No. 5), see PI. XI., fig. 2, probably part of the same collection as that 

 refen-ed to by Dr. Vaughan. Yet none of these closely resemble Seba's coral except in 

 the one fact that the forking is at a wide angle and occurs at variable distances along the 

 stems, and this growth-habit scatters the branches far and wide into an irregular open tangle. 



8. Porites Curagoa 2. (P. Guraqom secunda.) 

 [Cui-agoa, coll. Wayland Vaughan ; Wasliington.] 

 Syn. Porites jioi'ites Vaughan, Bulletin U.S. Fish Commission, ii. (1901) p. .314, pi. xxviii. 



Description. — The corallum, rising as a single gradually thickening stem, divides into a 

 cluster of wavy branches of varying thickness, by repeated l5ut irregular foiking, and at various 

 angles. The closeness of the cluster is due to the bending inwards of the prongs so as to 

 grow as nearly vertical as possible. The stems in a stock 13 cm. high and 16 cm. broad 

 may vary from 1 to 2 cm. thick ; they are smooth, round and sinuous, with " knee-bends," * 

 and aborted prongs. The living layer extends from .3 to Ti cm. deep. 



The calicles are shallow, about 1 -5 mm. in diameter. The walls near the growing points 

 show a zigzag wall-thread which later thickens as the septa and the rest of the calicle skeleton 

 thicken. It then seems possible to trace (1) a ring of wall granules upon the continuous 

 wall, (2) an inner ring of short septal granules, sometimes joined to and sometimes distinct 

 from the wall, and (3) a clear ring of conspicuous pall, visible to the naked eye as a central boss 

 in the calicle. These pali \a,vy in size and are mostly 5 in number, with a central tubercle, 

 which deeper down is occasionally seen to be united with the paU by the radial strands of a 

 columellar tangle. Groups of calicles occur without any columellar tubercle. 



The above description is based upon Dr. Vaughan's excellent photographs of this coral 

 and upon his descriptive text. The growth-form is specially interesting, and belongs to the 



* For an explanation of this term, see p. 18. 



