22 
of the state of preservation of Maccoyellcc from the district in question, I am 
at present of opinion that it is a Ilaccoyella, and in'obahly not far removed 
from 31. rejlecta, Moore, sp. If the curved line, possibly regarded by tlie 
author as the anterior, he looked on as tlie posterior cardinal margin, then 
the radial concavity traversing the shell will he in accordance with a similar 
depression always seen in specimens of the species mentioned ; the sculpture 
is also quite that of 3Iaccoyella, 
Genus — INOOEEAMUS (./. Sowet'hy, ms., 1814), Parkinson, 1819. 
(Trans. Geol. Soc., 1819, V, p. 55.) 
Obs . — It is a remarkable fact that, notwithstanding the abundance of 
this genus in the Ilolling Eowns Eormation (Lower Cretaceous) of Central 
(Queensland, it appears to l)e, with one doubtful exception, quite absent from 
the similar series made known to us by bores in New South Wales; at any 
rate, that is the present state of our knowledge. 
In onr U])])cr Cretaceous Series, however, as developed in the Wliite 
Cliffs Opal-field, it is moderately plentiful ; hut specimens arc always in such 
a wretclu'd state of preservation tliat it is practically impossible to effect 
specific identification with any degree of certainty. 
The specimens I have seen are always fragmentary, and either mere 
external impressions in the kaolinised rock of that field, or “ casts ” from 
which every fragment of test has been removed. No one specimen is 
sufficiently entire to enable me to speak with confidence as to its specific 
identity; hut the best preserved (PI. Ill, Figs. 6 and 7) are peculiar by their 
very short dorsal or cardinal margins and insinuation of the dorso-posterior 
margins. The valves possessed no great degree of convexity, and were 
ornamented by coarse concentric laminm of growth. 
Poc. — White Cliffs Opal-field, near lYilcannia, North-'West N. S. Wales 
{TFarlen W. G. 3Iackenzie). 
Ilor . — Upper Cretaceous (White Cliffs Opal Series). 
Colin, — Mining and Geological Museum, Sydney. 
