PERMIAN OSTRACODA FROM EASTERN AUSTRALIA. 
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inwards. Two spines at posterior end, one near dorsal margin and one 
on ventral margin, both protruding backwards. Surface otherwise 
smooth. Length, 0-82 mm. ; height, 0-54 mm. ; thickness, 040 mm. 
Paratypes. — (a) Left valve. Smaller than holotype; posterior end 
angulate and ventral margin straight. Length, 0*61 mm. ; height 
043 mm. (6) Eight valve. Shape and size similar to holotype. 
Observations. — Healdia chapmani is closely comparable with 
H. limacoides Knight, from the Permian of Eastern Missouri. It differs 
from it in the highest part ofi the curve on the dorsal margin being 
central and in the more angulate posterior end. It differs from 
H . subangularis Delo from Western Texas in the shorter length of the 
carapace. The species has been named after the late Mr. F. Chapman, 
who described many ostracoda from Australian deposits. 
Occurrence. — Holotype (Comm. Pal. Coll. No. 263) : Cattle Creek, 
II miles S.E. of Springsure, Queensland, below Waterfall (Lower 
Bowen Series). Paratypes (Comm. Pal. Coll. Nos. 264, 265) : Same 
locality as holotype. Also in sediments at Mt. Hope near Springsure 
(Lower Bowen Series). 
Genus CAYELLINA Coryell, 1928. 
Cavellina springsurensis sp. nov. (PI. IV, Figs. 6a, b.) 
Holotype. — Carapace medium sized, ovate. Dorsal surface arched, 
ventral slightly concave. Posterior thicker than anterior. Surface 
smooth except for vertical ridge at posterior end of each valve extending 
to nearly middle distance up dorsal margin. Eight valve overlaps left. 
Anterior end broader than posterior with widest portion just above 
middle. Length, 1-21 mm. ; height, 0-82 mm. ; thickness, 0*65 mm. 
Observations. — Cavellina springsurensis is distinct from any 
described species. It bears some resemblance to C. fittsi Kellett from 
the Upper Middle Pennsylvanian of Kansas in having a vertical ridge 
in the posterior portion. 
Occurrence. — Holotype (Comm. Pal. Coll. No. 266) : Cattle Creek, 
14 miles S.E. of Springsure, Queensland, below Waterfall (Lower Bowen 
Series). 
Cavellina aequivalvis sp. nov. (PI. IY, Figs. 7a, b.) 
Holotype. — Carapace small, subovate, with rounded anterior and 
posterior ends, slightly compressed. Yalves of equal size and shape, 
anterior edge broken. Both dorsal and ventral margins parallel. Length, 
1-06 mm. ; height, 0-62 mm. ; thickness, 0-67 mm. 
Observations. — This species closely resembles Cytherella aequalis 
Jones, Kirby and Brady (1884, pi. 6, figs. 15a, b) described from the 
Carboniferous limestone of Gare, Lanarkshire, England. The present 
form is placed in the genus Cavellina which was instituted by Coryell in 
1928 to include all Carboniferous and Permian species of Cytherella. 
There is no overlap of right valve in C. aequivalvis as is typical of the 
genus. 
