Ptiilobryri.] PELECYPODA. 85U 



Type in the Mus. Hist. Nat., Paris. 



Hab. Stewart Island, in 35 fathoms, type (Filhol) ; dredged off 

 Otago Heads ; Foveaux Strait, in 15 fathoms (A. Hamilton) ; near 

 the Snares, in 50 fathoms (Captain Bollons) ; Banks Peninsula (Ire- 

 dale) ; Cape Maria van Dienien. 



3. Philobrya meleagrina, Bernard, 1896. Plate 51, figs. 15, 15a. 



Hoclistetteria meleagrina, Bernard. Bull, des Naturalistes du Museum, ii, 

 1896. Philobrya meleagrina, Bernard, J. de Conch., xlv., 1897, 12; 

 11, i. ],2; pi.' 1, f. 3 : Suter, T.N.Z.I., xl, 354. 



Shell small, equivalve, inequilateral, rather thin, subquadrangular 

 to ovato-triangular, with faint radial riblets or smooth. Shells living 

 amongst the roots of Macrocystis are of somewhat irregular shape, 

 mytiliform, the beaks often much produced. Beaks approximate, 

 inclined toward the inner side, frequently produced, with a rather 

 small flat prodissoconch. Anterior end abruptly truncated, more or 

 less excavated, forming with the slightly convex dorsal margin an 

 angle of 100" or less. Posterior end forming an obtuse angle with 

 the dorsal margin, thence convex or almost straight ; basal margin 

 rounded, sometimes broadly angled towards the anterior and posterior 

 end. Area smooth, concave in front. Sculpture consisting of 8 to 12 

 faint radiate riblets, but in most examples the valves are smooth and 

 show only incremental hues. Epidermis thin, horny, forming imbri- 

 cating lamellae, and extending beyond the margins of the valves. 

 Colour white or light horny. Interior white, smooth, shining. Margins 

 smooth and oharp, slightly crenulate when the valves are costate. 

 Hinge-plate narrow, -vith a narrow anterior groove : sometimes, however, 

 in mytiliform specimens the hinge-plate is broad, strong, and the 

 typically long and narrow internal ligament is greatly developed, the 

 dorsal and anterior margins much thickened. Adductor-scar small, 

 oval, posterior Pallial line simple. 



Diameter Ant. -post. 2-5 mm. ; dorso-ventral. 2-5 mm. : thick- 

 ness, 1-1 mm. : prodissoconch. 0-5 mm. (type). Large specimens 

 have an ant. -post, and dorso-ventral diameter of 4-5 mm. 



Type in the Mus. Hist. Nat.. Paris. 



Hab. Stewart Island, in 35 fathoms, type (Filhol) ; Bay of Islands 

 (J. C. Anderson) : near Cuvier Island, in 38 fathoms (Captain Bollons) ; 

 Gisborne (A. Hamilton) ; Banks Peninsula (Iredale) ; Titahi Bay (Miss 

 Mestayer) ; off Lyttelton, in 100 fathoms (E. R. Waite) : off Otago 

 Heads (A. Hamilton) ; near Taumaki Island, in 10 fathoms ; near 

 the Snares and Bounty Islands, in 50 fathoms (Captain Bollons) ; 

 Foveaux Strait, in 15 fathoms ; Chatham Islands, in roots of Macro- 

 cystis (Professor H. B. Kirk) ; Macquarie Island (A. Hamilton). 



Remarks. This is one of the most variable species of the genus I 

 know. The fine riblets are represented by thin radial lines mostly in 

 specimens from deep water, but those found amongst kelp-roots show 

 usually no trace of costte, but very often deep concentric grooves. 



