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DESCRIPTIONS OF SIX NEW SPECIES OF SHELLS AND OF 



LEPTOMYA LINTEA, BUTTON, FROM NEW ZEALAND. 



By Heney Sutee. 



Read 9th November, 1906. 



PLATE XVIII. 



CoKNEOCYCLAS AucKLANDiCA, n.sp, PL XYIII, Figs. 7-7c. 



Shell small, inequilateral, oval, and somewhat inflated. Beaks not 

 prominent, rounded, situate at the posterior third ; prodissoconch 

 smooth, convex, passing without strong demarcation into the adult 

 valves. Anterior end convex, dorsal margin nearly straight, sliglitly 

 descending. Posterior end much shorter, regularly rounded. Basal 

 margin broadly convex. Sculpture consists of very fine concentric 

 striae. Colour light yellow ; interior slightly whitish. Hinge-plate 

 narrow. Eight valve with paired anterior and posterior laterals, two 

 cardinals, the anterior slender, broadly V-shaped, the posterior stouter, 

 elongately triangular, situate partlj' below aud behind the anterior 

 cardinal. Lett valve with single anterior and posterior laterals, two 

 cardinals, one in front of th-e other, the anterior tooth stouter, hook- 

 shaped, and the posterior very slender, directed backwards. Ligament 

 small, inset. Length 3-5, height 2"75, diam. 2 mm. (One of the 

 largest specimens.) 



Ilab. — The specimens used as type were collected many years back 

 by Mr. Mussou in a pond at Parnell, Auckhmd. Other localities are : 

 Ohaupo (C. Musson) ; Otaki Gorge (H. B. Preston) ; Heathcote 

 Estuary, near Christchurch, in slightly brackish water (H. S.). 



Type in mj collection. This species never attains the size of 

 C. Nov(s-zelandi(B. Prom young specimens of the latter it may be 

 distinguished by being more inflated and by having the beaks more 

 posteriorly. From C. Ilodglcini it is separated by the somewhat larger 

 size, the more oval form, and by being more inequilateral. 



Most of the specimens have above and behind aferrugineous coating. 



Venericakbia (Pledeomeris) Bollonsi, n.sp. PI. XVIII, Figs. 8-83. 

 Shell small, ovate, solid, slightly ine(iuilateral, and with nodulous 

 radiate ribs. Beaks approximate, but little anterior, high and erect, 

 prosogyrate, incurved ; pi'otoconch very small, pointed and smooth. 

 Anterior end with the dorsal margin descending and slightly concave, 

 thence subanguUirly rounded ; posterior end sharply convex, dorsal 

 margin descending, long, and a little convex, basal margin regularly 

 and broadly rounded. Lunule subcordate, finely striated. Escutcheon 

 lanceolate, long and narrow, minutely striate, bounded by a carina. 

 Sculpture: 14 strong radial beaded ribs with slightly broader 

 interspaces ; numerous concentric ridges, more prominent distally and 

 on the base. Colour brown, much lighter towards the beaks. Interior 

 white, porcellanous, margins strongly fluted. Hinge solid, right 

 valve with a stout triangular central cardinal, which is laterally 

 microscopically striate, anterior and posterior cardinals not well 

 developed, the anterior lateral tooth is distinct, the posterior very 



