878 PELECYPODA. [Filibrnnchia. 



Diameter Ant.-post., 44 mm. ; dorso ventral, 46 mm. : thickness, 

 13 mm. 



Type in the Dominion Museum, Wellington. 



Hab. Stewart Island, in 13 fathoms (type) ; near Cuvier Island, 

 in 38 fathoms (Captain Bollons) ; off Waipapa Point, in 25 fathoms 

 (E. R. Waite) ; Port Pegasus, Stewart Island, in 18 fathoms (Captain 

 Bollons) ; Preservation Inlet ; Banks Peninsula. 



Fossil in the Miocene and Pliocene. 



5. Pecten zelandiae, Gray, 1843. Plate 58, fig. 10. 



Pecten zelandlce, Gray, Dieff. N.Z., 260 ; Ereb. & Ter., 7, pi. 3, f. 7 ; C.M.M., 

 81; Crit. List, 50; M.N.Z.M., 170: Button, P.L.S. N.S.tt'., ix, 531. 

 P. Icetus, Gould, P. Bost. S.N.H., iii, 1850, 345 ; U.S. Expl. Exp., xii, 

 45H, atlas f. 571. P. iJiefjenbachi, Reeve, Conch. Icon., viii, 1852, f. 88. 

 P. multicostatus, Reeve, I.e., f. 173; M.N.Z.M., 171. 



Shell of medium size, rather thin, nearly equivalve, the ears very 

 unequal, ventricose, colour very variable, with numerous unequal 

 radiate squamose ribs. Beaks approximate, the protoconchs small, 

 triangular, sharply pointed, smooth. Anterior ears large, triangular, 

 the right with a deep quadrilateral byssal fissure : posterior ears much 

 smaller, triangular. Discs sharply angled above, separated from the 

 auricles by a strongly marked shoulder, regularly rounded below. 

 Sculpture : Ears with radial riblets crossed by concentric lamellae, 

 squamose ; the byssal area on the right anterior valve concentrically 

 lamellate, and a ctenolium on the margin of the valve ; discs with 

 numerous (about 40) unequal and inequidistant squamose ribs, the 

 interstices narrow, with fine incremental strise. Colour very variable- 

 rosaceous, light brown, purple, red, light to orange yellow, occasionally 

 with 3 or 4 paler rays. Interior white, or tinted with the same colour 

 as the outside, shining. Margins thin and sharp, lightly crenate. 

 Hinge smooth, a tubercle at the lower end of the anterior ears. Ee- 

 silifer obliquely triangular ; external ligament narrow and extending 

 the whole length of the hinge-line. Adductor-scar roundish, super- 

 ficial, slightly posterior. Pallial line simple. 



Diameter Ant.-post., 31 mm. ; dorso-ventral, 33 mm. : thickness, 

 13 mm. 



Type in the British Museum. 



Hab. Throughout New Zealand. Chatham Islands. Under rocks 

 and on roots of seaweeds, from low-water mark to about 25 fathoms. 



Fossil in the Miocene and Pliocene. 



Subsp. gemmulatus, Reeve, 1852. Plate 56, fig. 10. 



Pecten genunti]<itus. Reeve, Conch. Icon., viii, 1852, f. Ill ; C.M.M., 81 ; 

 Crit. List, 50 ; M.N.Z.M., 170. /'. ncozclanica, var. gemmulatus, Reeve : 

 Mutton, P.L.S. N.S.W., ix, 531. P. australis, Sowerby : Hutton, J. de 

 Conch., xxvi, 54 ; M.N.Z.M., 171 ; not of Sowerby. P. asperrimus, 

 Lamarck : Hutton, P.L.S. N.S.W., ix, 531 ; not of Lamarck. 



Distinguished from the species by the much more unequal radiate 

 ribs there are 12 to 20 prominent strong rounded and scaly ribs, 



