LAMELLIBRANCHIATA. 73 



VENERUPIS. 



Irregular in shape, inequilateral, gaping behind, three teeth in one 

 valve and two or three in the other, pallial sinus deep and broad. 



77. V. reflexa, Gray, Dieff. N.Z., ii., p. 250. Elongato-oval, 

 extremities obtuse, with rather distant concentric lamellre, higher and 

 rather reflexed at the posterior end ; interstices longitudinally striated, 

 occasionally sub-decussate ; umbones striated ; three hinge teeth in 

 each valve, the two posterior in the right, and the central tooth in the 

 left valve bifid. "White or brownish ; inside white with a purple spot 

 at the posterior end. Height, '8 ; breadth, 1'4. 



Chatham Islands. 



Very like V. exotica, Lamark, from Australia. 



78. V. forevis, Quoy, I.e., iii., p. 534. Ovato-quadrangular ; 

 umbones smooth ; margin strongly plicated ; concentrically lamellate, 

 interstices longitudinally striated ; three teeth in the left valve and 

 two in the right, the posterior bifid. White or brownish, inside white 

 with a purple spot at the posterior end. Height, '75 ; length, 1. 



Chatham Islands only. Tasmania. 



FAMILY PETEICOLID^I. 



Ovate, thin, swollen, inequilateral, equivalve, gaping at both ends ; 

 teeth two in each valve, unequal, the larger bifid ; pallial line remote 

 from the margin in front, broad and deeply sinuated behind. 



PETRICOLA. 



Ovate, transverse, thin, hinge broad. 



* 79. P. serrata, Deshayes, Proc. Zool. Soc., 1853. Elongate, 

 very broad, cylindrical ; dirty reddish ; extremities obtuse, gaping ; 

 longitudinally ridged, the ridges larger and denticulated at the anterior 

 end, thin in the middle, and more numerous and undulating at the 

 posterior end ; valves thin ; interior dirty white ; pallial sinus elon- 

 gate, apex obtuse, base broader. 



New Zealand (Cuming). 



FAMILY CARD IID^; . 



Cordate, swollen, equivalve ; cardinal teeth irregular ; laterals 

 remote, or none ; pallial line simple ; ligament external ; generally 

 radiately ribbed, rarely smooth ; posterior differently sculptured to 

 the front and sides. 



CARDIUM. 



Ventricose, umbones prominent, margins crenulated ; pallial line 

 more or less sinuated ; umbones sub-central. 

 World-wide. 



80. C. Striatulum, Sowerly ; C. pulchellum, Gray, Dieff. N.Z., 

 i\.,p. 252, nee Reeve. Sub-cordate, rather ventricose, thin, rosy white 

 varied with red, umbones generally white ; interior white varied with 

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