Late Cenozoic Ostracodes — Holden 
39 
Fig. 29. Sclerochilus sp. A. a-b, Specimen usnm 648787 ; a, lateral view of left valve; b, dorsal view. 
valve) T-12: length, 0.61: width, 0.10; height, 
0 . 26 . 
distribution; As fossil from T-12 (1 
valve) . 
discussion: Only one specimen of this 
species was collected at station T-12. The interior 
of the specimen is heavily encrusted, and so 
most certainly it belongs to the fossil suite. 
Sclerochilus sp. B. 
Figs. 30 a-c 
description: In lateral view: subovate; dor- 
sal margin broadly rounded; anterior and pos- 
terior margins equally rounded; ventral margin 
gently convex in posterior half, sharply concave 
in anterior half ; greatest valve height central ; 
length not quite twice the height ; surface 
smooth. In dorsal view: greatest width central; 
length 2-J times the width ; posterior half some- 
what more inflated than anterior half. 
Hinge weak: right valve apparently over- 
lapping left valve at dorsal extremities; faint 
groove in right valve to receive dorsal edge of 
left valve. Duplicature of even width. Adduc- 
tor muscle scar pattern of five elongate scars 
subcentrally located, all apparently divided; 
two oblique mandibular scars near venter above 
inturned area. 
dimensions: Specimen usnm 648788 (right 
valve) T-12: length, 0.46; width, 0.10; height, 
0.25. 
distribution: As fossil from T-12 (1 
valve) . 
discussion: The Hawaiian species bears some 
affinity to Sclerochilus contortus (Norman), 
1862 of Brady, 1880 from the Recent of 
Kerguelen Island, southern Indian Ocean, and 
from Head Island, New Zealand. The two 
species differ only in that the former is relatively 
higher. Brady’s forms, in turn, differ consider- 
ably from Norman’s illustrations by being 
shorter and with more evenly rounded ends. 
The single right valve dealt with here is 
poorly preserved. The adductor muscle scar 
pattern appears to be divided; however, this 
cannot be said with certainty. 
