'/7/c I'A'liinodenii I'^unut of Xottlli Africa. 389 



pentagonal with distal side usually somewhat concave; ocular pore 

 rather large, close to distal margin of plate; at center of each 

 plate is a well-marked secondary tubercle and spine, proximal to 

 which are several much smaller tubercles bearing miliary spines or 

 pedicellariae ; all oculars much exsert; genitals large, wider than 

 high, broadly in contact, pentagonal with proximal side concave; 

 madreporite large somewhat swollen and very fully occupied by the 

 pores; each genital plate bears 3-.") conspicuous secondary tubercles 

 and spines on the proximal side, with a number of miliary tubercles 

 about them; genital pores large-, close to distal angle of plate; both 

 ocular and genital plates, aside from the pores and the sparse 

 tubercles have a smooth and shining surface; anal system mm. 

 across, not very thickly covered with minute plates; there is no 

 conspicuous suranal but a plate, somewhat larger than the others, 

 adjoins genital 3, near its juncture with 2, and may be interpreted 

 as such ; there are no spinelets or pedicellariae on the periproct. 

 Peristome only 17 mm. across and hence only '22 h. d.; it is cover- 

 ed by a rather thick membrane in which are a considerable num- 

 ber of scattered small plates, some of which bear pedicellariae; 

 buccal plates not very large scarcely in contact with each other, 

 crowded with ophicephalous podicellariae; gill cuts broad and shal- 

 low, hardly recognizable. 



Primary spines all broken at tip. but it is evident that they were 

 more than 20, but less than 30 mm. long; they are nearly 2 mm. 

 in diameter at base ; the surface is very delicately striated with 30 

 or more parallel longitudinal furrows. Secondary spines 5-6 mm. 

 long, about half a millimeter thick at base, relatively few and well 

 scattered; on an interambulacral plate in the midzone there are 

 10-1-4, well-spaced; on adjoining ainbulacral plate, there are not 

 more than 3 or 4. Miliary spines about 4 mm. long, about '20 mm. 

 thick at base, tapering steadily towards tip but suddenly expanded 

 there into a thick flat-topped head, some - 20 mm. in diameter. 



Pedicellariae abundant everywhere, on long stalks. The globi- 

 ferous resemble closely those of P. agulhensis but are considerably 

 larger, as the valves are often nearly a millimeter long. The ojilii- 

 cepltalous too are like those of agulhensis but are somewhat larger. 

 The tridentate are very numerous and very varied; some are like 

 those of agulhensis with broad slightly curved valves, about - 50 mm. 

 long, meeting only at tip; but most have straight, narrow valves 

 60-2-20 mm. long, somewhat expanded near tip and more or less 

 in contact there. 



Colour of test white with a distinctly roseate tinge; all spines 



