Dr. J. E. Gray on the Genw5 Manouria. 215 



of commerce in several important particulars. That coral, which 

 generally grows from the undei'-surface of ledges of rocks in a pen- 

 dent position, has the polypes equally scattered on all sides of its 

 branches, and thus the animal caxi obtain food with equal facility on 

 all sides of the coral. 



Tlie Madeiran coral, on the contrary, seems to grow in a fan-like 

 manner, spreading out horizontally from the rock or other marine 

 body to which it is attached ; and it has the animal placed on each 

 side of the upper surface of the stem and branches, as though the 

 animal could only obtain nourishment on that part of the coral which 

 is exposed to the light, or at least is parallel with the surface of the 

 sea. 



This is the case with many, indeed I may say with all the corals 

 which grow in this expanded, fan-like manner. 



There is a species of coral which grows, and has the animal like- 

 wise distributed in the same manner, which is found in the seas near 

 the Sandwich Islands, and has hence been called Corallium seeu7i- 

 dum by Mr. Dana, but it is very different from the species here de- 

 scribed. The Madeiran coral is easily distinguished from that de- 

 scribed by Mr. Dana by the colour of its bark and axes, and the thick, 

 elongated, subsimple, subparallel branches. 



Secondly, this Madeiran coral appears to be normally of a white 

 colour, while the Mediterranean coral is of a bright crimson-red, and 

 has hence been called Corallium rubrum. The latter is sometimes 

 bleached white, or becomes so from some defect or malady in the 

 animal : it is rarely found naturally white, or more generally with 

 some portion of the coral white. I have never seen it naturally of 

 this colour, but I have seen some specimens with white portions ; and 

 I have been informed that these portions have been bleached by the 

 sudden application of heat or some other process. The Madeiran 

 coral, on the contrary, seems to be always white. 



The "White Coral" of commerce is a species of Caryophyllia 

 of Lamarck. 



If this coral could be obtained in any quantity from Madeira, it 

 would be a beautiful object for jewellers, and I have no doubt fetch 

 a good price. 



On the Genus Manouria and its Affinities. 

 By Dr. J. E. Gray, F.R.S., V.P.Z.S., etc. 



In the ' Proceedings' of this Society for 1852, p. 133, I described, 

 and in the quarto Catalogue of the ' Shield Reptiles in the Collec- 

 tion of the British Museum ' I described at greater length and figured, 

 the imperfect shield of a Tortoise which had long been in the posses- 

 sion of the Society, under the name of Manouria fusca. 



Dr. Cantor, in his ' Catalogue of the Reptiles of the Malayan 

 Peninsula,' describes a specimen of the same Tortoise under the name 

 of Geoemyda spinosa, considering it as the adult of that curious and 

 interesting species, and most unjustifiably copies my description of 

 the animal of that Tortoise as that of the animal belonging to the 

 shell which he was describing. 



