910 MR. G. F. ANGAS ON NEW AUSTRALIAN MOLLUSCA. [NoV. 28, 



duced, somewhat beaked, obtusely keeled from the umbones ; lateral 

 teeth finely serrated. 



Long. 7, alt. 5, lat. 3 lines. 



Hab. Johnson's Bay and Parramatta River, Port Jackson. 



This species resembles in external appearance the Mactra late- 

 ralis of Say, from South Carolina ; it is, however, flatter and less 

 sharply keeled, with the posterior dorsal slope longer and straighter, 

 and the umbones closer together, whilst the serrated character of the 

 lateral teeth would alone distinguish it from the American shell. 



LORIPES ASSIMILIS, u. s. (PL XLIV. fig. 8.) 



Shell somewhat triangularly orbicular, rather inflated, slightly 

 superficially excavated at the anterior side, solid, whitish, concen- 

 trically very finely elevately striated throughout ; margins crenate ; 

 cartilage in an oblique groove of the hinder hinge-margin. 



Long. 6, alt. 6, lat. 3| lines. 



Hab. New South Wales ; and Hobson's Bay, Port Philip. 



This species differs from L. icterica. Reeve, in being more solid 

 and inflated, more strongly concentrically ridged, and in the absence 

 of the diverging radiate strise of the latter. 



Mysia (Felania) adamsi, n. s. (PI. XLIV. fig. 9.) 



Shell depressly orbicularly elongate, white, shining, covered with 

 a very thin transparent horny epidermis ; concentrically very finely 

 irregularly striated, smooth and polished at the umbones ; lunule 

 very small ; margins simple. Hinge with two teeth in each valve, 

 one of which is bifid. 



Long. 6, alt. &^, lat. 2>\ lines. 



Hab. Port Jackson. Dredged in deep water. 



Mysia (Felania) jacksoniensis, n. s. (PI. XLIV. fig. 10.) 



Shell triangularly depressly orbicular, posterior side rounded, an- 

 teriorly somewhat obliquely produced, pale rosy flesh-colour, covered 

 with a light-green shining epidermis ; umbones produced, a})proxi- 

 mate ; concentrically finely irregularly striate, the lines of growth 

 strongly impressed at intervals ; interior pinkish. 



Long. 4, alt. A\, lat. 2| lines. 



Hab. Dredged in deep water in Port Jackson. 



Lepton adamsi, n. s. (PI. XLIV. fig. 11.) 



Shell triangularly ovate, rather convex, inequilateral, milky white, 

 somewhat transparent, thin, shining ; surface of valves finely con- 

 centrically striated, and minutely shagreened anteriorly and poste- 

 riorly, smooth in the middle ; anterior side short, rounded ; poste- 

 rior side ovate, widely plicate towards the margin ; umbones pro- 

 minent and slightly oblique ; superior margin convex ; the inferior 

 margin straight. 



Long. 6 1, alt. 5, lat. 2| lines. 



Hab. Port Jackson. 



