208 Annals of the South African Museum. 



thus R = l - 7r; or 2 - 2 br at half-way point; or 6 br at three-quarters 

 point. In the PIETER FAUKE specimen, R = 54 mm.; r = 20 mm.; 

 &r at half-way point, 13 mm.; br at three-quarters point, 7 mm.; 

 thus R = 2- 1 r ; or 4-1 6r at half way point ; or 7-7 br at three-quarters 

 point. Probably a large series of specimens w r ould show that there 

 is considerable individual diversity in these proportions, and very 

 likely, an increasing ray-length, with age. 



Colour in life: upper surface reddish orange, lower surface pale. 



Perhaps it ought to be added that it is not certain that the spe- 

 cimens identified by Bell are really tiibercalata : he does not say whether 

 he compared them with the type or not. Certainly Gray's figure does 

 not resemble at all closely any one of the three specimens at hand. 



CLADASTER MACROBRACHIUS * sp. nov. 

 Plate XIII. Figs. 1, 2. 



R = 40 mm.; r = 10 mm.; R, = 2-5r; br = iS mm. but at half- 

 way to tip it is only 9 mm. Disk large, somewhat convex but only 

 about 8 mm. thick, even at center. . Rays flat, tapering, at first 

 rapidly, then gradually to the blunt tip. Abactinal plates moderate 

 in both size and number, irregularly polygonal, with rounded corners, 

 thick and close together; papulae few, single, typically six about any 

 one plate on center of disk or base of rays but usually one or more 

 of the six, lacking. Each plate, in life, was evidently surrounded by 

 a marginal series of small, well spaced granules and bore on top, 

 several larger, more widely spaced granules, one of which was here 

 and there replaced by a large bivalved, more or less excavate pedi- 

 cellaria; in the preserved specimen (dry) all the top granules, some 

 pedicellariae and many marginal granules have been rubbed off but 

 each has left a shallow pit to indicate its location. Median radial 

 series of plates shut off from terminal plate by the meeting of the 

 five distal pairs of superomarginals ; series of plates adjoining radials 

 only extends as far as the fourth or barely to the fifth superomarginal. 

 Madreporite small (less than 2 mm. in diameter), pentagonal, situated 

 about 10 mm. from the disk margin. Superomarginals 13 or 14 on 

 each side of each ray, wider than long, more or less markedly tumid ; 

 like the abactinal plates, each is surrounded by a marginal series of 

 small granules, and in life was very sparsely covered by much coarser 

 and more widely spaced granules ; on the upper end of each plate, 

 where it is most markedly tumid, there are two or three (distally 

 one or none) large, shallow scars, which indicate that in life rather 



o^ =. long -|- jj()nj(i<ir = arm, in reference to the relatively long rays. 



