202 Annals of the South African Museum. 



P.F. 27<)S. Vusro de Gania Peak, N. 71 E., 18 miles, 230 fins. 

 Stones. 1 specimen, adult. 



Holotvpe, South African Museum, no. A 6415. 



This species has a very characteristic appearance due to the form 

 of the marginals, the absence of pedicellariae and the crowded adam- 

 Imlucral plates with their furrow-series of three spines. The form is 

 distinctly less pentagonal than in most members of the family, the 

 tips of the rays being markedly prolonged. The granulation both 

 above and below is noticeably coarse, but it is especially so on the 

 actinolateral plates. 



CERAMASTER PATAGONICUS var. EURYPLAX * var. nov. 

 Plate XIV. Figs. 1, 2. 



R = 32 mm.: r = 20 mm.; R = l-6 r. Form nearly pentagonal 

 but the sides are slightly concave. Abactinal plates tabulate, poly- 

 gonal, of diverse sizes and closely crowded, so that the sides are very 

 straight and clear cut, as in C. patagoniciis; radially the plates are 

 perfectly hexagonal and interradially they are rhombic ; they are 

 smallest at center of disk and near the marginal plates; the larger 

 plates have a marginal series of 12-14 coarse granules and 10-18 

 similar but slightly smaller granules are within the marginal series; 

 the latter have their outer sides quite vertical and the adjoining- 

 angles sharp; a central plate and the live basals are distinguishable 

 by their smaller granules. Superomarginal plates 10 or 11 on each 

 side of each ray or 20-22 on each s.ide of the pentagon; the inter- 

 radial pair are each 4 mm. wide and 2'5 mm. long, approximately 

 rectangular, with nearly straight edges; succeeding plates similar but 

 progressively shorter; there is little change in width until very near 

 the tip of the ray ; the central abactinal part of each plate is slightly 

 tumid, bare and smooth ; this bare area is largest distally and smallest 

 on the interradial pair; elsewhere the plates are closely covered with 

 a coat of granules of very uniform size, of which there may be 

 more than 200 on a plate. Terminal plate of moderate size, very 

 tumid, pentagonal, smooth. Madreporite small, wider than long, 

 1'75 mm. across, its outer margin 13 mm. from edge of disk. Infero- 

 rnarginals of the same number as the superomarginals; the interradial 

 pair underlie the interradial superomarginals but each succeeding 

 plate lies progressively more distal so that near the tip of the ray 

 the two series alternate ; in granulation the inferomarginals resemble 



* ivyvs = wide + /rAft? = plate, in reference to the very wide interradial 

 superomarginals. 



