WEST INDIAN ISLANDS PORITES. 43 



this same region. Such a search might lead to important results and show us whether 

 changes are gradually taking place in the Pontes fauna of the Islands. I make the suggestion 

 because, though other forms have been since gathered at Guadalupe, this one has not 

 reappeared, and further, because the fossil-forms of these islands do not yet show any close 

 resemblance with known living forms. The material for working this out is, I know, far too 

 limited to justify more than a doubt. 



On the suggestion made by Dr. Vaughan that this should be a type of growth-fonn, one 

 of his " formse " of the single branching species Poritcs pvritcs, see remarks p. 16. See also 

 below, P. Porto Pico 2. 



22. Porites Guadalupe 2. {P. Guadalupensis secunda) 

 [Guadalupe, coll. Lesueur; ? ] 

 Syn. Porites flabelliformis Lesueur, Mem. du Mus., vi. (1820) p. 289. 



Description. — The corallum is branching ; the branches are divergent, opposite and hori- 

 zontally arranged on a slightly flattened stem ; the branchlets flatten and fork at the tips. The 

 living layer extends to the base. 



The calicles ai-e " small, contiguous, spiny, and pentagonal." 



In addition to the above description, the height, apparently of the poly^js but really of 

 the stock, is given as 2'5 to 5 cm. The peculiarity of this Porites is its flattening tips and 

 perhaps the horizontal disposition of the branches round a central stem, although this is 

 not very clear from the description. Until fresh specimens are discovered from this same 

 locality, we shall never know exactly what this coral was like. 



There is an old specimen in the Paris Museum (No. Z 182/') with somewhat flabellate 

 tips to the branches, the branches themselves being both slightly flattened and divergent. 

 Though it is labelled, " P. clavaria, coll. Michelin," it is just possible that it may have been 

 one of Lesueur's larger specimens. It is more fully described below, see p. 87, P. West 

 Indies X. 9, PI. XIV. fig. 2. 



23. Porites Guadalupe 3. (P. Guadahipensis tertia.) 

 [Guadalupe, coll. Lesuem- ; ? ] 

 Syn. Porites astnmides Lesueur, Mem. du Mus., vi. (1820) p. 287, pi. .xvi. figs. 15, a, h, c. 



This is described and figured as an encrusting form with gibbous expansions. The 

 calicles are small, close together and circular or subpentagonal. 



In growing it spreads over foreign bodies which come in its way. It is thin, here and 

 there rising into irregular mounds, perhaps due to the bodies it has covered over. 



When the polyps are expanded, the colony has, according to the author, the appearance 

 of a small field covered with flowers. The general colom- is a beautiful sulphur-yellow with 



6 2 



