42 MADREPOKAKIA. 



The chief morphological interest in tliis coral lies in its sharing with the Trinidad 

 specimen the tliick trabecuhe, unlike any of llie known recent massive Furites. 



a. Cf. c. Geol. Dept. K. 2476. 



i- Geol. Dept. K. 1950. 



c. Cf. a. Geol. Dept. R. 2505. 



20. Porites Barbados 10. (P. Barhatm decima.) 



[Barbados (Pleistocene) ; British Museum.] 



BcscrijJtion. — This is a small, roughly egg-shaped mass, 3 cm. long and 2 cm. at its 

 thicker end. It appears to have been a complete stock. It is corroded, but not much worn, 

 and what looks Like the outline of a colony, creeping down its swollen top and encrusting its 

 sides, can still be made out round the base of the stock, while again the mass which it appears 

 to encrust shows signs of having been an earlier stage of the same Porites. Can this be the 

 starting-point of a branching form ? It looks as if it miglit be, and if so, it is of considerable 

 interest because of the very small size of its base, above which the first stem swells into an 

 ovate mass. Many branching forms early fall over and new colonies start from their sides 

 and thus build up tangles, the new stock always growing on the overturned old. It might 

 well be that some do actually begin to rise almost at once, that is without the formation of 

 any basal disk. On this subject see further, Table III. E. d., p. 136, and, on the falling over 

 of coral stocks, the last paragraph of p. 133. 



Tlie calicles are almost too corroded to give reliable details, but they w^ere at least - 

 1 ■ 5 mm. in diameter and distinctly depressed with conspicuous walls. 



a. Geol. Dept. E. 1282. 



21. Porites Guadalupe 1. (P. Guadalupensis prima.) 



[Guadalupe, coll. Lesueur ; ? ] 



Syn. Ponies dimricata Lesueur, Mem. du Mus. Paris, vi. (1820) p. 288. 



Description. — The corallum forms very delicate, thin branched stocks, some 5 cm. high 

 and more. The branches fork at wide angles, so that the whole is open and spread out, tlie 

 lateral branchlets even pointing downwards all round. The tips are flattened before forking. 

 The living colony is confined to the uppermost portions of the stock. 



The only other details of this coral to be gathered from the original description are 

 that, though the living colony is confined to the upper portions of the branches, it nevertheless 

 descends lower down than in {P. recta =) P. St. Bartholomew 1, see p. 53, and again that in 

 the divergent and oblique anangement of the branches it contrasts strongly with the close 

 grouping of the branches of that same coral. 



It is greatly to be desired that search slumlil lie made for new specimens of tliis coral in 



