980 PELECYPODA. [Eulamellibranchia. 



centric sharp ridges, decreasing in number, and getting higher at 

 both ends ; faint radiate striae are usually visible. Colour light 

 pinkish - brown, the umbones whitish, but darker at the apices. 

 Interior white, dull, the scars and borders of the margins polished, 

 the anterior lower part with radiate fine plications. Margins smooth 

 blunt. Hinge-plate strong, arcuate ; right valve with 4 cardinals, 

 the anterior small, vertical, and close to the much stronger triangular 

 tooth ; the third cardinal distant, horizontal, long and narrow ; the 

 fourth cardinal parallel to the former, a fine slender lamella. ; 

 2 anterior laterals, the upper one stronger, both corrugated ; left 

 valve with 3 cardinals, the anterior subvertical, thin, high, connected 

 above by a small hook with the second, subhorizontal, stronger 

 cardinal, forming together a broadly A-shaped tooth ; the posterior 

 cardinal a long slender lamella, subparallel to the median tooth ; 

 the anterior lateral forming a stout corrugated tubercle. Ligament 

 strong, almost extending to the end of the hinge-plate, with a stout 

 resilium of white colour. Adductor-scars subequal, pyriform. Pallial 

 line distinct, distant from the margin ; pallial sinus triangular, 

 slightly ascending, extending to the middle of the disc, its angle 

 pointing at the middle of the anterior scar. 



Length, 48 mm. ; height, 44 mm. : diameter, 22 mm. 



Type in the British Museum. 



Hob. North and South Islands ; common in the North, rare 

 in the South. Chatham Islands. The type is from the east coast of 

 the North Island. 



Maori. Hakari (teste Button). 



Fossil. Miocene and Pliocene. 



Sect. 4. DOSINISCA, Dall, 1902. 

 Type: Artemis alata, Kct-vc. 



Areas of the lunule and escutcheon pouting mesially, defined by a 

 pronounced sulcus, forming a posterior wing which recalls Phacoides ; 

 sculpture of fine, rather distant, sharp lamella?, sometimes with radial 

 striation ; valves thin ; pallial sinus deep and angular ; lateral tooth 

 entire. 



This group is distributed in Australia and Japan. (Dall.) 



I. Dosinia Greyi, Zittel, 1864. Plate 62, fig. 2. 



Dosinia Greyi, Zittel, Reise d. " Novara," Palaeontologie von Neuseeland, i, 

 pt. 2, 18ti4, 45, pi. 15, f. 11. D. Gratji, Zittel. C. Tert. M., 22 ; M.N.Z.M., 

 151 : Button, P.L.S. N.S.W., ix, 524 (2), i, 1887. 227 ; Tate, T.R.S. 

 S.Aust,, ix. 1887. 161 ; Plioc. M., 82 ; Index, 89. 



Shell rather small, orbicular, thin, inequilateral, with distant sharp 

 concentric lamellfe, the lunule raised at the middle line. Beaks raised, 

 inflated, incurved and directed forwards, situate at the anterior two- 

 fifths of length. Anterior end semicircular, the dorsal margin short 

 and convex ; posterior end broadly convex, the dorsal margin straight, 



