46 
PACIFIC SCIENCE, Vol. XXI, January 1967 
Fig. 35. Anchistrocheles jumata Brady, 1890. a-b, Plesiotype usnm 648749; a, right valve view of entire 
carapace showing overlap of left valve; b , dorsal view, c, Paratype sdnh 1065; internal view of left valve. 
cardinal angle ; inconspicuous curved lateral 
ridge roughly paralleling posterior margin. In 
dorsal view: carapace oblong except for com- 
pressed posterior; right valve overlapping left 
above hinge, overlapped by left valve above 
caudal process. 
Hinge unique, weak: small anterior tooth of 
left valve faintly stepped; smooth subtle me- 
dian bar; posterior element of two teeth. An- 
terior element of right valve a small tooth be- 
neath socket; dorsal margin extended into faint 
tooth which overlaps left valve anterodorsal to 
socket; stepped part of anterior left valve tooth 
fits between two anterior teeth of right valve; 
posterior element single tooth posterior to, and 
partially above, socket. 
Adductor muscle scar pattern a slightly in- 
clined vertical row of four ; single antennal scar 
just anterior to adductor group; single mandib- 
ular scar above adductor group. Duplicature 
wide; anterior vestibule deep, irregular; pos- 
terior vestibule apparently moderately deep ; 
single and bifurcate radial pore canals ex- 
tremely fine, with tendency to group; normal 
pores small, sparse, irregularly grouped, not 
coinciding exclusively with external pits. 
dimensions: 
PLESIOTYPE 
LENGTH 
WIDTH 
HEIGHT 
usnm 648754 
(right valve) HA 
0.35 
0.08 
0.16 
USNM 648754 
(left valve) HA 
0.35 
0.08 
0.16 
USNM 648755 
(entire) T-l 
0.41 
0.15 
0.17 
distribution: As fossil from T-l (1 
entire) ; Recent from HA (2 valves; 1 entire). 
Described by Brady (1890) from Suva Suva 
Bay, Fiji Islands at 4 fathoms, and from 
Manila Bay by Keij (1954). 
discussion: This species possesses features 
characteristic of the family Leptocytheridae ; 
especially of the genus Leptocythere , with re- 
