126 



spaces ; ribs obsoletely granulo-uodulose, except on the flat- 

 tened area posterior to the regularly rounded umbonal ridge, 

 where they are covered by depressed imbricating lamellae ; 

 inner margin of valve crenulated, denticulate under the umbo. 



Dimensions. — Length, 7 ; height, 4-5 millimetres. 



Locality. — Adelaide bore. A left valve (B.T.). 



Modiolaria Gorioensis, spec. nov. PL iii., fig. 4. 



Shell oval-oblong, sub-diaphanous ; umbo almost marginal, 

 •somewhat depressed, medial smooth area about two-thirds of 

 the length of the shell ; anterior radial area with about twelve 

 acute ribs narrower than the angular interspaces ; posterior 

 radial area with about 30 flat ribs with linear interspaces. 

 Inner margin of valve crenulated, denticulate under the umbo. 



Dimensions. — Length, six ; height, four millimetres. 



Locality. — Corio Bay, Victoria {B.T.). 



M. Corioensis is closely related to M. impacta^ Hermann, and 

 M. Cumingiana, Dunker ; from the first it differs by its finer 

 and numerous radii, and from the latter in being less gibbous 

 and by its wider medial area. 



Two other species of Modiolaria have been collected from 

 the oyster banks of the iVldinga cliffs, but in a too exfoliated 

 condition for diagnosis. 



Crenella globularis, spec. nov. PI. x., figs. 3a — 36. 



Shell small, thin, translucent, sub-globose, pearly within, 

 equivalve, inflated especially in the dorsal third ; umbos a little 

 anterior, obtuse, incurved, approximate ; surface regularly 

 cancellated; ligamental groove internal, lanceolate, extending 

 posteriorly; hinge line bordering the ligamental area, minutely 

 transversely denticulated; a small denticle termina^tes the 

 ligamental groove under the umbo ; margin of valves crenu- 

 latetl all round. 



Dimensions. — Length, 5 ; height, 6 ; thickness through both 

 valves, 7 millimetres. 



Localities. — Glauconitic sands, Adelaide bore, many 

 examples ; gastropod bed, near Morgan, one example; Muddy 

 Creek, Hamilton; Table Cape, one example {R.T.). 



This fossil differs only specifically from Stalagmium mar- 

 garitacea, C oi\r ^d^=Myoparo costatus, Lea, of the Eocene of 

 Alabama, which it resembles more than any other congener 

 known to me ; it is distinguished by its spherical shape and 

 cancellated ornament. C. elegans, Deshayes, of the Parisian 

 Eocene, is another closely related species. 



