1030 PELEOYPODA. [Eulamellibranchia. 



Diameter Ant. - post., 9-3 mm. ; dorso - ventral, 8-3 mm. : 

 thickness, 3 mm. 



Type in the British Museum. 



Hob. Stewart Island, type (C. Trail!) ; Taiaroa Head, in 45 

 fathoms (A. Hamilton) ; Banks Peninsula, in shallow water (Ire- 

 dale) ; Cuvier Island, in 38 fathoms (Captain Bollons) ; off Great 

 Barrier Island, in 110 fathoms. 



Fossil in the Pliocene. 



6. Myodora pandoriformis, Stutchbury, 1835. Plate 55, figs. 14, a. 



Anatina pandoriformis, Stutchbury, Zool. Jotim., v, 1835, 99, Tab. Sup., 

 43. f. 3, 4 ; Hanley, Cat. Rec. Biv. Shells, 25. Myodora pandorceformis, 

 Stutchb. : Reeve,' P.Z.S., 1844, 93 ; Conch. Icon., ii, pi. 1, f. 10. 

 M. pandoriformis. Stutchb. : Hanley, op. cit., pi. 10, f . 9 ; E. A. Smith, 

 P.Z.S., 1880, 581 ; ChaU. Rep., xiii, 64 ; Hutton, P.L.S. N.S.W., ix, 

 515; Index, 88; Pritchard and Gatliff, P.R.S. Vic., xvi (n.s.), 102. 

 H. brevis, Sowerby : H. and A. Adams, G.R.M., iii, pi. 98, f. 2 ; not of 

 Sowerby. 



Shell rather small, transversely elongate, subequilateral, moderately 

 solid, broadly truncated behind, with distant fine concentric line, 

 the right valve very convex, the left flat or faintly concave. Beaks 

 not much raised, sharply pointed, and directed backward. Anterior 

 end narrowly convex, the dorsal margin faintly rounded, slowly 

 descending ; posterior end vertically broadly truncated, the dorsal 

 margin a little excavated and slowly descending, ventral margin 

 regularly convex. Sculpture : Right valve with rather distant, sharp, 

 but not high, concentric riblets, more prominent posteriorly, where a 

 ridge runs down from the umbo to the lower angle of the truncation ; 

 left valve with much fainter lirse, the posterior oblique ridge obsolete ; 

 both valves are microscopically rather distantly radially striated, and 

 have very close concentric lines, which are interrupted by the radii, 

 and distinctly discontinuous. Colour greyish-white. Interior pearly, 

 radially distantly sulcate. Margins smooth. Hinge with a small 

 central resilium and a straight elongate ossicle. Adductor-scars un- 

 equal, the anterior irregularly roundish, the posterior round. Pallial 

 sinus shallow, convex. 



Diameter Ant. -post., 18mm.; dorso -ventral, 12mm.: thickness, 

 5 mm. 



Type in the British Museum. 



Hab. Stewart Island (C. Traill) ; Port Pegasus, Stewart Island, 

 in 18 fathoms (Captain Bollons) ; Banks Peninsula (Iredale). Also 

 Australia and Tasmania. 



7. Myodora rotundata, Sowerby, 1875. Plate 55, fig. 15. 



Myodora rotundata, Sowerby, P.Z.S., 1875, 129, pi. 24, f . 8 ; E. A. Smith, 

 I'.Z.S., 1880, 580; Hutton, P.L.S. N.S.W., ix, 515; Index, 88. 

 M. rotunda, Sowerby : Hutton, M.N.Z.M., 137 (lapsus calami). 



Shell roundly subtrigonal, very inequivalve, white, both valves 

 concentrically strongly striated, with 2 slight angles on the posterior 



