157 



with a straighter post-dorsal slope, and more pointed behind. 

 It agrees with C. Isabella in the number and strength of the- 

 lamellse, but is otherwise different. 



Chione propinqua, Tenison-Woods. Plate xiv., figs. 7 and 8. 



Reference. — Proc. Eoy. Soc, Tasmania for 1876, p. 113. 



Transversely oval, umbo a little in front of the centre ; an- 

 terior end broadly rounded ; posterior side a little attenuated, 

 its margin roundly truncated. Ornameuted with many (more 

 than 20) raised rounded concentric ribs, becoming lamellar at 

 the extremities ; ribs and the narrower interspaces are concen- 

 trically striated ; the interspaces crossed by transverse broadish 

 riblets, equal in width to the intervening spaces. Margin of 

 the valves finely crenulated. Pallial line near the margin, the 

 siphonal inflection rather shallow, narrowly triangular, rounded 

 at the apex. 



The species varies somewhat in shape and in the number and 

 thickness of the concentric ribs ; fig. 8 represents the typical 

 form, fig. 7 represents a more oblong and narrower shell, whilst 

 others are more attenuated than the type, even becoming sub- 

 rostrated. 



Tenison-AVoods compares his species with the existing 

 C. conularis, but the greater affinity is with C. mesodesma, Quoy 

 and Gaimard, from which it differs most conspicuously by the 

 coarser radial ornamentation. 



Dimensions of the type. — Antero-posterior diameter, 24 ; 

 nmbo-ventral diameter, 19 ; sectional diameter of one valve, 6 

 millimetres. 



Localities. — Table Cape (B. 31. Johnston /) ; lower and 

 upper beds at Muddy Creek, but common in the latter only. 



Chione Corioensis, spec. nov. Plate xvi., fig. 1. 



Sub-quadrately ovate, sub-depressed, inequilateral ; nmbo 

 small, situated in the anterior third ; anterior side narrowed, 

 abruptly rounded ; posterior side broader, and obliquely rounded 

 at the end ; the post-dorsal margin is horizontal and" straight ; 

 ventral margin much ecurved. Lunule ill-defined. 



Surface smooth and shining, with distant linear concentric 

 sulci, the intervening flat sub-imbricating interspaces, becoming 

 thread-like at the front and the two extremities ; a few indis- 

 tinct fine radial corrugations appear towards the antero-ventral 

 margin. Angulated lines of colour are visible in the umbonal 

 and median regions. Margin of valves plain. 



Dimensions. — Antero-posterior diameter, 7'25 ; umbo-ventral 

 diameter, 675. 



Locality. — In the calciferous sandstone at Corio Bay, Gee- 

 long. 



This species bears a strong resemblance to the young of 



