450 R. ETHERTDGE, JTJN., ON AUSTRALIAN TERTIARY ECHINODERMS. 



Genus Sctjtella, Lamarck. 



S. tamboemis, M'Coy (? M.S.) I c. p. 22 ; Mount Tambo, Vic- 

 toria. 



In addition to the foregoing, species of the following genera 

 have been indicated, viz. : — 



Cardiaster, Woods, Geol. Obs. S. Aust. 1862, p. 77 ; Mount Gam- 

 bier, South Australia. 



Gidaris, Woods, Geol. Obs. S. Aust. 1862, pp. 76, 81 ; Mount 

 Gambier, South Australia. 



Echinus, Sturt, Two Expds. Int. S. Aust. ii. p. 254, pi. 3. fig. 11 ; 

 Murray Cliffs, South Australia. 



Schizaster, Duncan, Annals Nat. Hist. 1864, xiv. p. 168 ; Ade- 

 laide District, South Australia. 



EXPLANATION OF PLATE XXI. 



Fig. 1. Hemipatagus Woodsii, R. Etheridge, jun., dorsal surface, nat. size. 

 Mordialloc, Victoria. 



2. Ventral view of the same, nat. size. 



3. Side view „ „ „ 



4. Anal „ „ „ „ 



5. Apical disk, considerably enlarged : a, madreporiform body ; b, genital 



plates ; c, ocular plates. 



6. Primary tubercles on the interambulacral plates, enlarged. 



7. Primary tubercles on the ventral surface, showing their union with 



the scrobicular circle, enlarged. 



8. Hemipatagus Forbcsii, Woods & Duncan, side view, nat. size. Mount 



Gambier, South Australia. 



9. Spatangns purpureus, Miiller, apical disk after Desor (Synopsis des 



Echinides, t. 44, f. 1). 

 10. Psammeckinus Woodsi, Laube, outline drawing, showing the apical 

 disk ; 10 a shows the natural size. Banks of the Murray river, 

 South Australia. 



