Neiv Species of Yictorian Mollusca. 191 



Cuna planillrata, sp. nov. (PI. XL\^II., Figs. 13-17). 



Shell small, white, glossy, rather inflated, subequilateral, 

 aequivalve, semitransparent. Beaks prominent. Prodissoconch 

 small, smooth. Dorsal margins straight, ascending so as to 

 almost form a right angle. Ventral margin much rounded. 

 Lunule and escutcheon elongate and inconspicuous. Valves 

 sculptured with numerous, close, concentric ridges, which are 

 flattish, and continue to the ventral margin, this sculpture 

 being clearly seen from within. Muscle scars evident. The 

 pallial line, owing to the transparency of the shell, is not easily 

 followed, but may be observed in worn specimens. Inner 

 margin not denticulate. 



Dimensions of Type. — Length, 2.50 ; breadth. 2.25 : depth 

 of single valve, 1 mm. 



Locality. — Dredged between Phillip and French Islands, 

 Western Port ; about 5 fathoms. 



Ohs. — In general contour and ornament the species somewhat 

 recalls Neolepton antij)odum, Filhol, but is immediately separ- 

 able by the hinge characters. The shell varies in colour, speci- 

 mens of a pinkish hue having been obtained. The present one 

 adds another species to our scanty representation of the genus. 

 Tlie genus, erected by Hedley in 1902, includes many species 

 from Australian waters, and embraces such extreme forms as 

 C. praecalva, Hedley, and C. haniata, Hedley and May. The 

 generic location of small bivalves has in many instances proved 

 a matter of considerable difficulty, and we think the diversity 

 of characters allowed and described in many species of Cuna by 

 the author of the genus will enable us to class under it some 

 shells which we have hitherto been unable to place. The hinge 

 characters alone show great variation, and this species is no 

 exception, the cardinal tooth, though triangular, being very 

 elongated. 



Type in Mr. C. J. Gabriel's collection. 



Montacuta nitens, sp. nov. (PI. XLVTL, Fig. 7). 



Shell minute, white, shining, very inequilateral, smooth, 

 swollen at the umbones, which are inconspicuous and situated 

 near the front, equivalve. 



