298 PROCEEDINGS OF THE MA.LACOLOGICAL SOCIETY. 



three nodulous ribs, the two posterior ones close together, sutures 

 slightly crenulated; one row of eyes between the first and second 

 rib. Posterior valve with the mucro terminal, minutely punctate, 

 a concentric marginal row of nodules, interspersed with eyes. Girdle 

 narrow, leathery (dry specimen !), with narrow white stripes below the 

 sutures. Colour light pink over the jugum, minutely dotted with 

 white, margined by rows of triangular white spots ; central and 

 lateral areas reddish brown, variegated with white on some of the 

 intermediate valves. 



Anterior valve with 10 irregularly spaced slits, teeth pectinate; 

 intermediate valves with 1 slit on each side; posterior valve with 

 a low, smooth, and rounded callus. Length 17, breadth 7 mm.; 

 divergence 70°. 



Hah. — Foveaux Strait, in 18 fathoms (Capt. J. Bollons), one specimen. 



The specimen was kindly lent me by Miss Mestayer, of Wellington. 

 As the shell contains the dried-up animal, which I did not venture 

 to remove, the inside could not be described. I have an anterior and 

 intermediate valve dredged in 10 fathoms near Open Bay Island, 

 west coast of the South Island, also obtained from Capt. J. Bollons, 

 which belong to a nearly allied species. The anterior valve has two 

 concentric rows of nodules near the margin, eight radiate rows of eyes, 

 the whole of the smooth surface covered with minute white dots ; 

 there are 8 slits, the teeth pectinate. Inside purple in the centre. 

 The intermediate valve is flesh-colour like the anterior valve, minutely 

 dotted with white, central areas with a number of low wrinkles in 

 front of the lateral areas, the latter with two radiate rows of rounded 

 nodules, between which the eyes are situated. Sinus deep, flat, 

 minutely denticulate, sutural laminae short, broadly rounded. One 

 slit on each side, the valve callus distinct, white, the remainder light 

 purple. Divergence 90°. 0. nndosus is no doubt closely allied to 

 0. rugulosns, Angas, from Port Jackson, Australia. Type in 

 Miss Marjorie K. Mestayer's collection. 



