178 
RECORDS OF THE AUSTRALIAN MUSEUM. 
LITTLE-KNOWN and UNDESCRIBED PERMO-CAR- 
BONIFEROUS PELECYPODA in the AUSTRALIAN 
MUSEUM. 
By R. Etheridge, Junr., Curator. 
(Plates xxxi. - xxxiii.) 
Genus Stutchburia,* gen. nov. 
In our Permo-Carboniferous formation are two bivalves that 
have been variously referred to Orthonota by Morris, Cardinia by 
Dana, and one of them to Pleurophorus by DeKoninck, the deter- 
mination of the last named author having been at various times 
accepted by myself and others ; possibly also one or more of the 
shells from the same series of rocks, termed Cypricardia by Dana, 
may be congeneric. I have, however, for some time past, from 
the edentulous nature of the shells in question, doubted the pro- 
priety of these references. 
The species are Orthonota ‘l costata , Morris ( = Pleurophorus 
morrisii , DeKon.), and 0 . 1 compressa , Morris, which may, or 
may not be only the internal cast of 0. costata. To these may 
perhaps be added Pleurophorus biplex , DeKon., and P. randsi , 
mihi. The internal structure of the two first, and particularly 
of 0. ^ costata is known to some extent, but that of the third very 
little, and of the fourth not all. It is by no means certain that 
P . biplex , and P. randsi are congeneric with 0? costata and 0 ? com- 
pressa , and in consequence are left for the present in Pleurophorus. 
At the same time there is still an undescribed form in our Marine 
Series, that appears to be generically identical with Pleurophorus: 
this will be described later. 
In form 0. ? costata and 0. 'I compressa are narrow, transversely 
elongate, and more or less compressed Molluscs, inequilateral in 
the extreme, with simple pallial lines, strongly marked muscular 
scars, particularly the anterior, which are complex, and, so far as I 
can ascertain, edentulous, at any rate the examination of a very 
large number of internal casts has failed to reveal the presence of 
hinge teeth. In the place of the latter the cardinal margins were 
very much thickened, particularly at the extremities, and in all 
probability this was accompanied by an internal ligament. In 
the face of these combined characters the reference of the species 
* Named in honour of Samuel Stutchbury, the first Government 
Geologist of New South Wales, as it then was. 
