102 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
Dimensions of holotype: Length, 2-15 mm.; height, 146 mm.* 
approximate thickness of carapace, 0-8 mm. 
Remarks: The high, compressed shell of this ostracod is characteristic 
of the genus Cyprinotus. In outline it closely resembles Cyprinotus 
dentato-marginatus (Baird), which has been recorded by Sars (1889) 
from lagoons near Rockhampton. It differs from this recent species, 
however, in having the shell much more closely punctate, the valves 
slightly higher and nearly twice as large, and in the presence of the 
well-defined marginal zone pierced by numerous radial pore canals. It 
might be mentioned here that two species of Cyprinotus found in 
Australia today attain a length of over 2 mm. 
Although this species is not uncommon in some of the samples from 
The Narrows, owing to its large size and the subsequent crushing of the 
material, very few undamaged valves have been found. It has been 
possible in some cases, however, to reconstruct the shape from various 
fragments of the valves, and the above description is based in part on 
the information so obtained. The species is moderately long-ranged, and 
individually of no value as a zonal index. Moreover, it is generally rare 
in its occurrence, and in very few of the bore-core samples examined 
has it been found to be really abundant. The outstanding characteristics 
are the very finely and closely punctate shell, and the well developed 
marginal zone pierced by the radial pore canals. Variation in the number 
and arrangement of the radial pore canals and in the width of the 
marginal zone has been observed. In some individuals the radial pore 
canals are all of equal length, but in others Ihey are of two and sometimes 
three different lengths, though always alternating in a regular manner. 
Sometimes they are very close together and almost contiguous throughout 
their length, but in other individuals they are more widely separated. 
Generally they appear to end in the bulbous enlargement. The width 
of the chitinised zone also varies in different individuals, and it is usually 
somewhat wider anteriorly and posteriorly than it is ventrally. It 
might also be mentioned that in some young and immature individuals 
no trace has been found of the radial pore canals. In some individuals 
the shell is thin, rather feebly calcified, and fragile, but in others it is 
heavily calcified, much more solid, and quite opaque. The recent 
Cyprinotus is generally considered as a subgenus of Cypris, and belongs 
to the subfamily Cypridinae, members of which are capable of swimming 
as well as creeping. The species has been named after the very finely 
and closely punctate shell of this ostracod. 
Localities and Age: Bores 1, 3, 4, 5, 6, 12, 13 14 (see species 
occurrence charts), parish of Targinie and Rundle, county of Deas 
Thompson, The Narrows, between Gladstone and Rockhampton. This 
species has a vertical range of at least 182 feet, and its actual range 
may be considerably greater. Probably Miocene. 
Genus Ilyodromus Sars, 1894. 
Genotype: Ilyodromus obtusus Sars, 1894. 
Diagnosis: Carapace in lateral view oblong. Dorsal margin 
variously arched. Ventral margin practically straight to gently sinuated.. 
Valves equal, or left slightly larger than right. Carapace compressed. 
Hinge short, edentulous, somewhat thickened. Surface of valves usually 
ornamented with distinct lines or riblets, but sometimes smooth or very 
delicately striated. 
