32 
THE BIRDS OF AUSTRALIA 
4. Cave Owl Tyto novce-hollanditz troughtoni sub.-sp. nov. 
troughtoni — Ellis Le G. Troughton, Mammologist, Australian Museum, 
Sydney. 
Distribution. — Nullarbor Plain (South Australia). 
Notes. — Usually singly or in pairs, frequenting the Nullarbor Plain. 
It roosts and nests in blow-holes and underground caves, venturing forth 
at night in search of prey. Food: small lizards, small mammals, and 
rodents. 
Nest. — In a blow-hole, eggs deposited on the bare sand. 
Eggs. — Two, white and oval, texture of shell coarse, with a faint 
gloss. Eggs taken on the Nullarbor Plains, in November, 1931. 
Description. — Type, adult female, collected at Ooldea, East-West 
Line, South Australia, by Messrs Troughton and Wright on 16 October 
1921, Registered Number 026568, Australian Museum, Sydney. Differs 
from the typical Masked Owl (Tyto novce-hollandioe) in its smaller size, 
lighter coloration on the back, and in having fewer spots on the under- 
parts. Measurements : total length, 460 mm. ; wing, 326 ; culmen, 26 ; tail, 
161 ; tarsus, 75. 
Females of the Masked Owl are noticeably larger and darker than 
the males; the type of the Cave Owl, however, which is a female, is com- 
parable to an average-sized male of the Masked Owl. 
5. Tasmanian Masked Owl Tyto castanops Gould 
cas -tan-ops — Gk, castanon, chestnut; Gk, ops, face. 
Distribution. — Tasmania. 
Notes . — Also called Chestnut-faced Owl. Usually singly or in pairs, 
frequenting forests of large and thinly scattered trees skirting open coun- 
try. It is similar in habits and economy to the Masked Owl. The sexes 
differ considerably in size, the female being larger, more powerful, and 
darker in coloration than the male. 
Nest. — In a hollow in a tree or in a cliff. 
Eggs. — Not recorded. 
6. Grass Owl Tyto longimembris Jerdon 
lon-gi-m em- bris — L. , longus, long; L., membrum, limb. 
Distribution. — Northern Territory, Queensland, New South Wales, 
and Victoria; also occurs in India, China, the Philippine Islands, New 
Caledonia, and Fiji. . , 
Notes. — Usually singly, frequenting grass-lands, chiefly of the coastal 
areas Very little has been recorded of its habits. It rests during the day 
in “squats” or “hides” under a tussock of grass. Food: rodents, large 
insects, and frogs. 
Nest. — Under or in a tussock of grass. 
Eggs. — Usually four, white, oval in form. Breeding-season: May 
to July. 
