The Echinoderm Fauna of South Africa. 



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nearly pentagonal as long as wide; the oral shields seem to be in 

 contact with the lirst pair of side arm-plates. Adoral plates rather 

 large, slightly curved, tetragonal with rounded angles, wider within, 

 where they meet, than without. Oral plates very small, hut each 

 bears three big, club-shaped, subequal oral papillae, 2-3 times as 

 long as thick. As usual in OphiomUrella there is a distinct papilla 

 or tentacle-scale on the inner side of the oral tentacle-pore, which 

 seems to be borne on the lirst under arm-plate. Teeth about 4, the 

 upper squarish but the lowest thick and narrow, pointed, not unlike 

 one of the oral papillae. No tooth-papillae. First under arm-plate 

 small, somewhat pentagonal, longer than wide; succeeding plates 

 pentagonal a little wider than long, with distal angles rounded, all 



Fig. 2. Upper side of part of disk and arm of OphiomUrella corynephora sp. nov. 



Some of the spines removed. X 10. 



except first two well separated ; they rapidly increase in relative length, 

 and distally, are very small and rather narrow, scarcely three-fourths 

 as wide as long. Side arm plates large, meeting above and below, 

 the spine ridges becoming more and more prominent distally, where 

 the arms are quite ''knotted"; each plate carries 6 (or basally 7) 

 spines, of which the first (uppermost) is longest and may equal two 

 arm-segments while the sixth or seventh is shortest, little exceeding- 

 one segment; the upper spines are pointed but the lowest two or 

 three are blunt and thickened at tip, becoming more or less club- 

 shaped; all the spines are smooth except the lowest which may be 

 more or less prickly at tip. Tentacle-scale large, but narrow, blunt 

 and flattened, about half as long as under arm-plate. Colour (dry): 

 - nearly white; specimens in alcohol have a faint pinkish tinge 



