MOLLUSCA 277 
Family OSTREIDA. 
OSTREA Linné, 1758. 
OSTREA CORRUGATA Hutton. 
Ostrea corrugata Hutt., Cat..Tert. Moll., 1873, p. 35. 
O. discoidea E. A. Smith, Voy. ‘‘Erebus and Terror,’’ Moll., 
1874, p. 7., pl i., fig? 15 (not of Gould). 
Stations 6, 9. 
Family PINNIDA#. 
ATRINA Gray, 1840. 
ATRINA ZELANDICA Gray. 
Pinna zelandica Gray, Yate, N.Z., 1835, p. 310. 
P, senticosa Gould, Proc. Bost., S.N.H., ii., 1850, p. 312. 
Station 20. 
Family CRASSATELLITIDA. 
CYAMIOMACTRA Bernard, 1897. 
CYAMIOMACTRA PROBLEMATICA Bernard. 
Cyamiomactra problematica Bernard, Bull. Mus. Hist. Nat.. 
Paris, 1097, pol meee. 
Station 4; Dredge Station A. 
CYAMIOMACTRA PROBLEMATICA, TRUNCATA var. nov. 
Differs from the species in the short sub-trapezoidal form; the 
anterior end being short and rounded, the posterior end truncate, 
with a distinct angle towards the basal margin; between this 
and the beaks the valves show a distinct angle. It is an extreme 
form of the variable species, and well worthy of a varietal 
distinction, though intermediate forms are sometimes met with; 
they, however, are never so distinctly angled. 
Length, 4mm.; height, 3.5 mm.; diameter 2mm. 
Type in the Canterbury Museum, Christchurch. 
Station 4. 
PERRIERINA Bernard, 1897. 
PERRIERINA TAXODONTA Bernard. 
Perricrina taxodonta Bernard, Bull. Mus. Hist. Nat., Paris, 
No. 7, 1897, p. 312, fig. 3 mm text. 
Station 4. 
