The Echinoderm Fauna of South Africa. 403 



in the interporiferous areas there are small primaries, though not in 

 great number. In ambulacrum III the plates are high and have a 

 well developed vertical pore-pair just distal to tin- centre--, as the 

 apical disc (which is anterior to the center) is approached the pore- 

 pairs lie more and more towards the outer side of the increasingly 

 lower plates. The apical system is small, compact and elongated: 

 there are four large genital pores and a greatly elongated rnadre- 

 porite ; from ocular III to a line joining the posterior margins of 

 genital pores 1 and 4 is not quite 3 mm. hut from that line to the 

 distal tip of the madreporite in interambulacram 5 is nearly 4 mm. 

 The peripetalous fascicle is very distinct, obviously depressed below 

 the test level and about a millimeter wide; it does not bend in at 

 any interradius and posteriorly has an evident narrow squarish out- 

 ward bend. Peristome not very much sunken, about 21 mm. wide 

 and its length not quite half as much; its anterior margin is '29mm. 

 from anterior end of test. Sternum and subanal plastron considerably 

 projecting but the surface of the subanal plastron is nearly flat and 

 almost horizontal. There are, on each side of the plastron, two large 

 tube-feet and apparently only 3 plates enter the fasciole. Periproct 

 12 mm. high and 7 mm. wide, pointed at both ends; its upper end 

 is just below the ambitus, so no part of it is visible from above; its 

 lower end is 6 or 7 mm. nearer the mouth than its upper, so oblique 

 is the surface on which it is placed. 



The holotype, S.A.M. No. A 6451, of this new species is a dead 

 but not waterworn test from Onrust River, near Hermanns, Cape 

 Province. There is also a second specimen in the collection but it 

 is from an unknown locality and has no label. It is somewhat 

 damaged and is also a little deformed, the ventral surface on the 

 left side being somewhat pushed in, forming a hollow, where, on the 

 opposite side of the test there is a slight outward arching of the 

 surface. 



This remarkable spatangoid combines to a very striking degree the 

 characters of Spatangus and of Brissus. The petals, the mouth and 

 the form of the posterior part of the test are quite like Sjxihingus, 

 while the presence of the peripetalous fasciole (but not its course), 

 the form of the anterior half of the test and the form and position 

 of the periproct are much like Brissus. The proximal part of the 

 anterior' poriferous areas of petals II and IV are very nearly com- 

 plete and normal, not more or less reduced as in Sputangus. In the 

 tuberculation of the test the new genus is unlike either of the others 

 for the primary tubercles are much more numerous, than in */></ fungus 

 while they are much larger than in Brissus. In some particulars, 



