WEST INDIAN ISLANDS PORITES. 37 



coral. Minute pali, up to 5, appear in a circle too straggling to be conspicuous to the naked 

 eye. A columellar tubercle or a central pit can be made out in the less rapidly solidifying 

 calicles. 



In transverse sections the axial strand is an open, lamellate reticulum ; the cortical layer 

 is almost solid. 



This coral, though aljout the same size, is qixite different in the manner of its branching 

 and in the texture of its calicles from P. Barbados 2. The forking, though irregular in the 

 sizes of the prongs, is yet not so irregular as that of the latter coral. 



There is only one stem («) which, when gathered, was alive ; with it are two other specimens 

 which appear to belong to it, although doubts may be legitimately expressed : — 



b. Is a corroded forking stem with rather more conspicuous calicles than «, Ijut with 

 traces of a very similar section to the stems and somewhat similar forking. This is only 

 provisionally placed here. 



c. Eepresents a corroded, encrusted mass, showing the section of a stem very similar to that 

 of a, and on it two young colonies, one a minute disk in its epithecal saucer, and the other 

 considerably older and rising into two forking peaks about 1 cm. high. The calicles are a 

 little smaller, and the walls rise as ii-regularly trabecular ridges. What little experience we 

 have of early growth stages in the Stony Corals seems to indicate that the calicles of the very 

 young colonies are smaller than those of the adults, and moreover show other differences. It 

 is clear, however, that we can only provisionally class this specimen here. 



a, b. Zool. Dept. 99. 6. 26. 11. 



c. Zool. Dept. 99. 6. 26. 10 (part). 



15. Porites Barbados 5. {P. Barbata; quinta.) 

 [Barbados (Pleistocene), coll. Franks ; British Museum.] 



Under this heading we provisionally group a number of fossilised and semi-fossilised 

 fragments of branching Porites, which for the purposes of description may be divided as 

 follows : — 



A number of beach-worn, gravel-coloured specimens, of various sizes, but all showing in 

 the sections a remarkable contrast between an immense, openly reticular, axial strand, and a 

 comparatively thin, dense cortical layer. Many of the worn fragments consist solely of this 

 axial reticulum. 



a. The largest specimens. Geol. Dept. E. 2557. 



b. The only specimen showing remains of pi'obablyj 



young calicles near a spongy terminal; with aV „ E. 2193. 



microscopic slide. j 



Ci. A great number of smaller much worn fragments. „ E. 2559 'part). 



Ci. Three fragments selected from the above with a great deal of chalky wliite colour 

 about them, not much worn and showing traces of the calicles. The skeletal elements 



