Marshall and Murdoch. — i\'ew Fossil Species of MoUusca. 257 



inwards, long, narrow, and concave above, sculptured with rough irregular 

 lines of growth ; the posterior margin forms a broad uniform curve from 

 the ear to the centre of base, thence the curve gradually becomes steeper. 

 Interior with shallow radiating grooves corresponding with the external ribs ; 

 adductor impression large, indistinct ; hinge broken ; margin of the valve 

 sharp and undulating. 



Dimensions (right valve) : Height, 76 mm. ; length, 60 mm. ; diameter, 

 13 mm. 



Locality, Waipipi, in a fine bluish-grey sand. Collector, P. Marshall. 



Type to be presented to the Wanganui Museum. 



The description is derived from a right valve. The species belongs to 

 the L. lima group, and may be distinguished from other of our fossil forms 

 by being shorter comparative to its height, and by the fewer and more 

 distinct ribs. 



Crassatellites subobesus n. sp. (Plate XIX, figs. 2, 3.) 



Shell elongately ovate, inequilateral ; anterior area short and convex ; 

 posterior attenuated, the end obUquely truncated ; continuous with the 

 curve of the umbo, and extending to the lower margin of the truncation 

 is a broadly rounded ridge, the area above being flattened or slightly concave 

 towards the posterior end, giving the dorsal area a winged appearance. 

 Beaks less than one-third from the anterior end, incurved, and directed 

 forward. Lunule deeply impressed, oval ; escutcheon long, narrow, and 

 concave. Sculpture consists of small, rounded, concentric riblets, rather 

 less than two per millimetre, and about the same width as the interspaces, 

 on the posterior dorsal area irregular, mostly coarse striations ; towards 

 the base the ribs are more or less irregularly developed and spaced, with 

 a number of growth-striae in the interspaces. Marginal contour : The 

 anterior end from the beak steeply declining, straight, thence broadly 

 rounded ; the base a wide sweeping curve, becoming flattened as it 

 approaches the posterior end ; posterior dorsal margin sloping downwards, 

 straight or slightly concave, the end obliquely truncated. Interior of left 

 valve-margin smooth ; adductor impressions and pallial lines impressed. 

 Hinge with three diverging cardinals, united above, the posterior slender, 

 the lower limbs of the two anterior narrowly separate ; posterior lateral 

 forms a long rounded rib with a deep groove above ; anterior area a broad 

 shallow groove, above which is a stout rib ending abruptly at the anterior 

 end of the umbonal margin. 



Dimensions : Height, 32 mm. ; length, 54 mm. ; diameter of perfect 

 specimen, 20 man. 



Locality, Wharekuri. Collector, P. Marshall. 



Type to be presented to the Wanganui Museum. 



The species is perhaps nearest to C. obesus (A. Adams) = trailli Hutton ; 

 the latter is distinctly triangular, and has a less winged appearance 

 posterio-dorsally. 



The material consists of one perfect specimen and a left valve ; the 

 former is filled with matrix, and it appears too risky to attempt to separate 

 the valves. 



Lucinida levifoliata n. sp. (Plate XX, figs. 1, 2, 3, 4.) 



Shell orbicular, subglobose, nearly equilateral, juvenile examples more 

 lenticular ; beaks contiguous, directed forward, sharply incurved, and termi- 



9— Trans. 



