110 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
less regular in its pattern and tends to resemble that of the well-known 
recent form Newnluvmia fenestrata King. In some individuals, also, the 
posterior overlap of the right valve appears to be greater than in others. 
Cypridopsis belongs to the sub-family Cypridopsinae, members of which 
are capable of swimming as well as creeping, and are most abundant in 
permanent, shallow, still waters. The species has been named after the 
ornament which generally is linearly tuberculate. 
Localities and Age: In The Narrows Tertiaries : Bores 1, 3, 4, 5, 6, 
12, 13, 14 (see species occurrence charts), parishes of Targinie and 
Bundle, county of Deas Thompson, between Gladstone and Rockhamp- 
ton. This species has a proved vertical range of only 82 feet, but its 
actual range may be somewhat greater. Probably Miocene. 
Cypridopsis compressa Chapman, 1935. Plate VI, fig. 7. 
Holotypc: F. 7852, University of Queensland Collection. Locality: 
Gully on portions 118, 119, 120, parish of Bundamba, county of Stanley, 
about 5 miles S. of Goodna, S.E. Queensland. Geological Horizon: 
Redbank Plains Series. 
Descnption: Carapace medium-sized, in lateral view arcuately ovate 
to broadly reniform, highest slightly behind middle. Height greater 
than one-half of length. Dorsal margin strongly arched. Ventral 
margin concave in median region. Anterior extremity well rounded, but 
somewhat truncated dorsally. Posterior extremity more broadly and 
evenly rounded. Valves only moderately convex, with convexity fairly 
regular. Position of greatest thickness of carapace located slightly 
behind middle. Valves subequal, right slightly overlapping left 
anteriorly, ventrally, and posteriorly. In profile ovate, with anterior 
extremity compressed and posterior somewhat inflated. Surface of valves 
smooth and unornamented. Rosette of five muscle scars, placed slightly 
anteroventrally of midpoint, conspicuous. Shell thin, fragile, chitino- 
calcareous, and translucent to opaque. 
Dimensions of figured specimen from the Petrie Series: Length, 
1-03 mm. ; height, 0-65 mm. ; approximate thickness of carapace, 0*5 mm. 
Remarks: In describing this species from the Redbank Plains Series 
in 1935, Chapman had at his disposal only one small sample of ostracod- 
bearing shale obtained from a surface outcrop. In this rather weathered 
material he found the carapace valves of this species strongly calcified, 
and, owing to their opacity, apparently he was unable to see muscle scars 
on any of the valves. Recent examination of additional samples, how- 
ever, has resulted in the discovery of a number of these valves with 
translucent shells clearly showing a rosette of five muscle scars. The 
species, accordingly, has been found to be identical with that recognised 
in the Petrie Series material, and, with the additional material available, 
a more complete description has been given. 
As Chapman (1935, p. 68) has remarked, Cypridopsis compressa 
“ bears a fairly close resemblance to Cypridopsis picta (Straus), a fresh- 
water form found in Norway, France, and Belgium.” It differs from 
