Oleobis ROBUSTA, sp. nov. 



Description.— The following is the description of a left 

 valve — the best specimen found — Shell large and ovoid, 

 inflated, the cast being flattened for about half an inch 

 from the anterior and dorsal margins. Beak anteriorly 

 situated,prominent, overhanging the hingeline and incurved. 

 From the appearance of the cast, the shell substance was 

 somewhat thick, particularly near the beak. Ventral 

 margin broadly and regularly curved, anterior and posterior 

 margins semi-circular, the anterior and prominent umbo 

 preventing what would otherwise be a regularly oval shell. 

 Anterior adductor impression oblong, about | of an inch 

 along its greatest dimension, which is parallel to the mar- 

 gin, well defined but shallow, and situated about £ of the 

 distance between the ventral margin and the apex of the 

 shell. Pa)lial line indistinct but apparently simple. Hinge 

 line curved and edentulous. There is no trace of sculpt ore 



Dimensions. — Length 4 i 



ches 



height 2f inches ; deptt 



of cast of left valve J of ai 



inch. 





Loc. Burrier (D); Junct 



i I 



Yalwal Creek and Shoal- 



haven River CS;. 







Hor. AVandrawandian Series. 



Obs. Only two specimens were found, both casts, the 

 type coming from Burrier. On comparing them with other 

 specimens of Cleobis, we liixl that the nearest resemblance 

 is to the species of Dana originally described as Maeonia 



contour, which apart from the umbo forms a regular oval. 

 M. tjrmidis on the other hand is more oblique and inflated, 

 with recurved not incurved umbos, and in addition evidently 

 has a relatively thinner shell. 



1 Geol., Wilkes, U.S. Esplor. Exped , p. 597, pi. 6, f. 8. 



