Prune sus capricornensis n. sp. — WOODLAND 
541 
COLOUR IN LIFE: Above lateral band, green- 
ish; below band, silvery; lateral band silvery, but 
distinguishable from silver of belly by its more 
intense mirror-like finish; running from dorsal 
edge of pectoral base the full length of the up- 
per limit of the lateral band a narrow (5.0 in 
width of lateral band ) intense blue band termi- 
nating at root of caudal fin; a small blue spot 
on upper half of caudal fin scaly sheath; bluish 
crescent along upper 2 A of base of pectorals; 
dorsals, caudal, and distal half of pectoral fins 
faintly dusky, other fins pale; peritoneum black. 
COLOUR IN FORMALIN: Above lateral band, 
area lying under margin of each scale with dark 
pigmentation; lateral band black with a sugges- 
tion of the blue of the narrow band in its upper 
limits; area below lateral band pale; scaly sheath 
at base of caudal fin with two dark patches de- 
rived by anastomosing of lateral band; narrow 
bluish crescent on pectoral base persisting; col- 
our of fins as in life. 
ECOLOGY: Heron I. is a coral atoll 50 mi. from 
the Australian mainland (23° 27' S., 151° 57' 
E. ). In the cooler months (Mar.-Aug.) im- 
mense schools of atherinids are common over 
the reef flat when it is flooded at high tide. All 
individuals taken from these schools proved to 
be a new species (P. capricornensis ) . 
This fish was always seen swimming at depths 
of 1-3 ft. At low tides and during the warmer 
months it probably lives in open waters. The 
little tuna, Euthynnus alleteratus affinis (Can- 
tor), which normally restricts its movement to 
open water, will venture on to the reef flat to 
feed on P. capricornensis. 
Examination of alimentary canals of two adult 
fishes revealed various planktonic Crustacea, but 
the bulk of ingested material was unidentifiable. 
Females in spawning condition were recorded 
in Aug. 1956. 
ACKNOWLEDGMENT: I would like to thank 
Richard J. Slack-Smith for donating -specimens. 
REFERENCE 
Schultz, L. P., E. S. Herald, E. A. Lachner, 
A. D. Welander, and L. P. Woods. 1953. 
Fishes of the Marshall and Marianas islands. 
U. S. Nat. Mus. Bull. 202, 1: 1-685. 
