[Proc. Eot. Soc. Victoria 19 (N.S.), Pt. II., 1906.] 



Art. VIII. — Four New Echinoids from the Australian 



Tertiari/. 



By T. S. hall, M.A., 



University of Melbourne. 



(With Plates XIII. -XVI). 

 [Read 1.3th December, 1906]. 



The present paper contains descriptions of 

 Echinoneus dennanti, n. sp. 

 Prenaster aldingensis, n. sp. 

 Brissopsis tatei, n. sp. 

 Schizaster sphenoides, n. sp. 

 Advantage of the opportunity has been taken to figure and re- 

 describe Schizaster abductus, Tate, which was not very fully 

 diagnosed by the author, and was not illustrated. 



All the species are of Barwonian age, that is, belonging to the 

 oldest of our Tertiary series. 



Echinoneus dennanti, n. sp. 



Test elongate, slightly wider just behind the apical system. 

 Flattened dorsally and actinally, depressed, with a thickly 

 rounded ambitus. Of the four genital openings the posterior 

 lateral pair are slightly the largest and are separated by about 

 their own width. 



Ambulacra similar, flush, continuous from apex to peristome, 

 broadest at the ambitus. Poriferous zones narrow, straight, not 

 sunken. Pairs of pores very numerous. On the abactinal sur- 

 face a line joining the pores of each pair is normal to the length 

 of the zone. Towards the ambitus and actinally this line 

 becomes more and more oblique, so that near the peristome the 

 pores tend to, but do not quite, become arranged in a single linear 

 series, the pores of each pair being closer together than those of 

 the next succeeding pair. 



