LAHELLIBRAXUHIATA. 75 



single cardinal tooth in the right valve ; anterior muscular impression 

 double. 



Widely spread. 



84. C., sp. ind. Anterior margin concave, umbones rather pointed 

 and bent forward, translucent, inflated, white. Height, '38; length, '38. 



Stewart's Island. 



1 notice, in Woodward'' 's Manual of the Moll/isca, that a species of 

 Gri/ptodon is known from New Zealand, but I have not been able to 

 ascertain its specific name. 



FAMILY UNGULINID^J. 



Sub-orbicular, closed ; hinge of two diverging bifid cardinal teeth, 

 without laterals ; ligament marginal. 



MYSIA. 



Equivalve ; two unequal cardinal teeth in each valve ; the anterior 

 of the left and the posterior of the right bifid ; ligament external. 



85. M. zealandica, Gray, Dieff. N.Z., ii., p. 256. Eather com- 

 pressed, smooth, very slightly concentrically striated, rather solid ; 

 opaque white. Height, 75 ; length, '75. 



Massacre Bay. 



86. M. globularis, Lam ark, I.e., vi.,p. 231. Orbicular, inflated, 

 umbones rather prominent ; very finely concentrically striated, thin, 

 pellucid. Horny white. Height, 1 ; length, 1'12. 



Stewart's Island, 14 fathoms. Australia. 



87. M. nOV3B ZGalandiSB, Reeve. Orbicular, very much in- 

 flated, umbones scarcely prominent ; strongly concentrically striated, 

 umboues smooth ; rather solid. Dirty white. Height, '4 ; length, '4. 



Kapiti ; Cook Strait. 



FAMILY EKYCINID^;. 



Thin, often transparent, and sometimes gaping ; hinge straight, 

 with one or two cardinal teeth ; lateral teeth compressed or none. 



KELLIA. 



Sub-orbicular, sub-equilateral, closed, smooth or concentrically 

 striated ; one valve with two cardinal teeth near together and a distant 

 lateral tooth ; the other with a single concave cardinal and a distant 

 lateral tooth ; ligament internal or sub-marginal. 



Widely spread. 



88. K. Cydadiformis, Deshayes(?), Trait elem., pi. 11, ff. 6-9. 



Ovato-orbicular, inflated, smooth, pearly white, covered with a thin 

 yellowish olive epidermis. Height, "4 ; length, '5. 

 Stewart's Island. Australia. 



PYT2IINA. 



Equivalve, equilateral, umbones -small, left valve with two small 



