14 



Annals of the South African Museum. 



at the ambitus, and smaller on the dorsal surface and on the base 

 of the test. 



Interambulacral plates high, each bearing a large primary, imper- 

 forate, slightly crenulate tubercle with an areola of moderate size ; 

 these tubercles are largest at the ambitus, where they are surrounded 

 by a narrow band of small tubercles and granules. Above the 

 ambitus, and on the base of the test, the primary tubercles become 

 smaller ; above the ambitus the surrounding band of granules 

 becomes much wider. At the ambitus and continued on to the base 

 of the test there is a row of secondary tubercles at the external 

 margin of the area. 



Peristome of moderate size. 



FIG. 1. Coptosoma capcnse, sp. nov. Ambulacral and interambulacral areas, x 2. 



The bigeminal pores extending from the peristome almost to the 

 margin of the base seem to distinguish this from other species of 

 Coptosoma. The form of the test is similar to that of the type 

 species, C. cribrum, Desor, but the granules, especially on the inter- 

 ambulacral areas, are much more extensively developed. 



Portions of three tests have been found, the largest and most 

 perfect of which is here figured. In all cases the apical disc is 

 missing. 



The only other remains of echinoids found in this deposit are some 

 strongly ridged spines of Cidaris, and a portion of the test of an 

 irregular form which may perhaps belong to Cassidulus. 



