10 
PACIFIC SCIENCE, VoL XXI, January 1967 
Fig. 4. Bairdia sp. a-c, Specimen usnm 648723; a, lateral right valve view of entire female carapace; 
b, dorsal view; c, anterior view, d, Specimen sdmh 1031 ; internal view of male left valve showing ventrally 
located adductor muscle scar pattern. 
distribution: As fossils from AR (1 valve; 
1 entire). 
discussion : Initially, this species was thought 
to be a dimorphic form of Bairdia attenuata. 
Both species have a distinct concavity in the 
posterodorsum ; but this feature is present only 
in the smaller right valve of B. pseudofoveolata. 
. .Bairdia sp. is closely related to B. foveolata 
{part ini') of Brady (1880), who illustrates two 
forms under this name which are certainly dis- 
tinct species. The present species resembles 
those of his plate 8, figures 1 a—f. Excluding 
figures 2 a-f from this discussion, B. sp. is 
wider in dorsal view, and more ventrally in- 
flated in anterior view, than is B. foveolata of 
Brady, 1880. Brady lists B. foveolata as ranging 
in depth from 7 to 1,150 fathoms. Unfortu- 
nately he does not specify at which depths the 
particular "varieties” of that species occur. 
The illustration of Bairdia bradyi Bold, 1957 
(new name for B. foveolata Brady, 1868$, not 
Bosquet, 1852), does not closely resemble those 
