

BY C. HEDLEY. 475 



beach of the south end of More ton Island, about half a mile north 

 of the sandhills. 



Chione capricornea, n.sp. 



(Plate ix., figs.24-25.) 



Shell massive, tumid, ovate, umbo prominent, posterior margin 

 subtruncate, anterior rapidly rounded. Colour either uniform 

 cream, cream with a few scattered brown dashes, or broad radi- 

 ating stripes alternately cream and brown, lunule usually brown, 

 interior pale yellow. Sculpture : about 36 narrow smooth con- 

 centric ribs, which near the anterior side are apt to be dislocated 

 or to end prematurely; those continuing become sharper and 

 more crowded, posteriorly they widen out for three-quarters of 

 the length, then close up to end abruptly at the escutcheon. The 

 ribs are about one-quarter the width of their deeply rounded 

 interspaces, which are ornamented by close engraved concentric 

 lines varying from six to twelve per furrow. The furrows are 

 also crossed by dense microscopic scratches which under magnifi- 

 cation offer the pattern of a brick wall. Lunule deep, cordate; 

 escutcheon narrow, both roughened by fine concentric lamellae. 

 Inner valve-margin finely crenulate except dorsally. Pallial 

 sinus narrow, sharply angled. Length, 47; height, 40; depth of 

 single valve, 17 mm. 



Hab. — Mast Head Reef, Queensland; 20 fathoms. 



Young shells of this species were mistaken for C. toreuma 

 Gould. The adult valve, now described, came to hand after my 

 paper on the Mast Head fauna was completed, and shows the 

 species to be distinct. The young shells, as often happens in 

 this genus, are rounder than the adult. 



Chione toreuma Gould, and C. embrlthes Melvill & Standen, 

 are the nearest relations of the novelty. By its lunule it is inter- 

 mediate between them, but its greater length in proportion to 

 height distinguish it from either. 



These two species present such difficulty that a brief discussion 

 of them may be acceptable. I find G. embrithes to range from 

 the Gulf of Carpentaria through Torres Strait to Moreton Bay. 



