Venericardia.] PELECYPODA. 905 



Subgen. 1. VENERICARDIA. s. str. 



KEY TO SPECIES. 



A. Right valve with 3 well-developed cardinal teeth. 



a. Ribs rounded ; interstices narrower than the ribs ; lunule 



cordate ; interior stained with purple . . . . australis. 



b. Ribs sharp ; interstices and ribs subequal ; lunule almost 



circular ; interior pure- white . . . . . . di/ficilis. 



B. Right valve with 3 cardinal teeth, the anterior and posterior feeble. 



a. Valves suborbicular, with about 28 fine crenate ribs ; lunule 



.small, ovate ; yellowish, spotted with brown or red . . amabilis. 



b. Valves ovate, with 14 strong beaded ribs ; interstices a little 



broader than the ribs ; lunule subcordate ; colour brown Bollonsi. 



c. Valves subtrigonal, with 14 to 16 nodulous ribs, the interstices 



of the same width ; lunule lanceolate ; colour brown, 

 sometimes with concentric reddish bands . . . . zdandica. 



C. Right valve with a very strong triangular cardinal tooth, the 



anterior cardinal feeble, the posterior cardinal absent ; valves 

 ovato-trigonal, with 11 ribs . . . . . . . . corbis. 



1. Venericardia australis, Lamarck, 1818. Plate 58, fig. 16. 



Venericardia australis, Lamarck, A.s.V., v, 1818, 610 ; Gray, Dieff. N.Z., 

 256; Quoy and Gaimard, Voy. Astrol., iii, 1835, 480, pi. 78, f. 11-14; 

 Index, 93. Carditn australis, Lam., Grit. List, 47 ; M.N.Z.M., 158 ; 

 Button, P.L.S. N.S.W., ix, 527 ; C. Tert. M.B.M., 361. 0. purpurata, 

 Deshayes, P.Z.S., 1852 (1854), 100, pi. 17, f. 12, 13; M.N.Z.M., 159. 

 C. lri' ! < t/ln'/i. Reeve, Conch. Icon., i, f. 22. Venericardia intermedia, 

 Hutton, 0. Tert, il., 1873. 24. 



Shell suborbicular, inequilateral, swollen, radially closely ribbed, 

 brownish - white. Beaks obliquely recurved. Anterior end short, 

 broadly convex, the dorsal margin slightly concave ; posterior end 

 produced, subtruncated, the dorsal margin slowly descending, lightly 

 convex ; basal margin broadly rounded. Lunule small, cordate. 

 Sculpture consisting of about 20 to 22 nodulose radiating ribs, the 

 nodules on the hinder side often subspinose ; the interstices narrower 

 than the ribs ; concentric growth-lines distinct. Colour whitish to 

 light brown, frequently with reddish spots at the umbones. Interior 

 porcellanous, white, more or less marked with rosy or purple at the 

 anterior and posterior ends. Margins plicated, thick. Hinge-area 

 broad and heavy ; the right valve with 3 strong cardinal teeth, all 

 finely transversely striated ; left valve with 2 cardinal teeth. Liga- 

 ment strong, not very long, external. Adductor -scars subequal. well 

 impressed. Pallial line distinct, simple. 



Length, 46 mm. ; height, 39 mm. ; diameter, 26 mm. 



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



Hob. Throughout New Zealand and Chatham Islands ; Kermadec 

 Islands (Captain Bollons). It is common in Tasman Bay (Q. & G.). 

 but not in the Hauraki Gulf. 



Maori. Purirnu (teste Hutton). 



Fossil. Miocene and Pliocene. 



