8 
PACIFIC SCIENCE, Vol. XXI, January 1967 
Fig. 2. Terminology of the lateral outline of the 
genus Bairdia (adopted from Sohn, I960). 
Carapace terminology of the Bairdia lateral 
outline has been adopted from Sohn. Unlike the 
cytheracid carapace, Bairdia does not have a pos- 
terior and anterior margin per se, these being 
more conveniently considered as continuations 
of the dorsal and ventral margins, respectively. 
Bairdia kauaiensis n. sp. 
Figs. 3 a—i 
Bairdia amygdaloides Brady, 1880. Rept. 
Voyage Challenger , Zool. 1, pp. 54-55, pi. 9, 
figs. 
diagnosis: Large, somewhat posteriorly- 
pointed carapace, greatly and evenly inflated; 
smooth to finely pitted surface; and similarly 
shaped anterior and posterior vestibules. 
description : Carapace large (maximum 
length about 1.2 mm) ; left valve overlapping 
right valve except at pointed caudal process; 
ventral and dorsal margins broadly, evenly 
rounded. Right valve: dorsoposterior slightly 
concave, sloping about 40° ; dorsal margin 
straight to slightly convex, sloping about 10- 
15°; dorsoanterior straight, sloping about 30°; 
ventral margin gently concave; ventroanterior 
bluntly rounded; ventroposterior slightly con- 
cave, entire surface densely but faintly pitted. 
Hinge typical for genus; adductor muscle 
scar pattern of about eight or nine smaller 
scars, basically five scars encircling a larger 
scar with two scars below these; two small 
mandibular scars anterior to lower adductor 
scars. 
Anterior and posterior vestibules equally 
large, with about same proportions ; radial pore 
canals fairly abundant, straight, simple. 
Fig. 3. Bairdia kauaiensis n. sp. a-b, Holotype USNM 648719; a, lateral view of female right valve showing 
overlap of left valve; b, dorsal view, c, Paratype sdnh 1026; internal view of male right valve, d, Paratype 
USNM 648720; muscle scar pattern of right valve, e, Paratype USNM 648721 ; internal view of male right 
valve, f, Paratype sdnh 1027; penultimate left valve, g, Paratype sdnh 1028; left valve of third from last 
instar, h, Paratype sdnh 1029; left valve of fourth from last instar, i, Paratype sdnh 1030; left valve of fifth 
from last instar. 
