148 



Locality. — Oyster-beds of the River Murray Cliffs at the 

 Nor'-West Bend. 



It is with some hesitation that I refer this little species to 

 Sacchia, as I have had no opportunity of examining an authentic 

 species of this genus, also because of the great resemblance it 

 bears externally to the lenticular species of Diplodonta, par- 

 ticularly D. Aclamsi and D. Jacksonensis, Angas ; but the den- 

 tition and the broad cartilage pit are not those proper to 

 Diplodonta. 



FAMILY EKYCINID^E. 

 Leptum crassum, Tate. 

 Beference.— -Trans. Phil. Soe, Adelaide, 1879, t. 5, f. 9, p. 130. 

 A thick transversely-oval shell. 



Locality. — Gastroped bed of the River Murray Cliffs, near 

 Morgan. 



Lepton planuisculum, Tate. 

 Beference. — Op. cit., t. 5, f. 12, p. 130. 

 A thin quadrately-ovate shell, with a produced umbo. 

 Locality. — Oyster beds of the Aldinga Cliffs. 



Kellia micans, spec. nov. Plate xix., fig. 13. 



Shell minute, inequilateral, rather thick, convex ; umbones 

 small, depressed ; anterior side somewhat produced ; posterior 

 side shorter, roundly truncated at the extremity ; the dorsal 

 margin is considerably oblique on both sides ; there is no 

 lunule. Surface smooth and shining, and ornamented with 

 concentric stria? ; alternating bands of varying width of opaque 

 white and bluish-slate colour. Left valve with one small car- 

 dinal denticle, in front of which is a stout laminar tooth ; there 

 is also a faint short lateral tooth on the posterior side. 



Dimensions. — Antero-posterior diameter, 3 ; umbo-ventral 

 diameter, 25 ; sectional diameter of left valve nearly 2 milli- 

 metres. 



Locality. — Muddy Creek. 



Montacuta sericea, spec. nov. Plate xiv., fig. 6. 

 Shell transversely ovate, moderately depressed, very inequi- 

 lateral, rather solid, glossy, and sculptured with very fine lines 

 of growth. The umbones are small, curved over towards the 

 front, slightly produced, and situated at about one-fourth of 

 the total length from the anterior end. The anterior-dorsal 

 margin is short, oblique ; imperceptibly excavated before the 

 umbo, then gradually rounding into the sharply-curved ex- 

 tremity ; the post-dorsal margin is much longer, at first almost 

 horizontal and straight, afterwards a little arched and oblique. 

 The ventral margin is nearly horizontal. The left valve ha& 



