186 
RECORDS OF THE AUSTRALIAN MUSEUM. 
Log. and Horizon. — Farley, near West Maitland — Lower Marine 
Series ; ? Wollongong, Illawarra District — Upper Marine Series. 
Genus Limoptera, J. Hall. 
(35th Ann. Report N.York State Mus. Nat. Hist., 1884, p. 406a.)* 
Limoptera h permocarbonifera, sp. nov . 
(PL xxxii., figs. 1 - 2). 
Sp. Char. — Shell obliquely subrhomboidal, length and width 
almost equal, but the latter somewhat the greater, produced 
postero-ventrally; valves very unequal, the left convex, the right 
more or less flattened, but the greatest convexity of the latter 
immediately below the umbone; hinge line straight, probably as 
wide as the shell ; ligamental area not well preserved, but appar- 
ently wide and deep beneath the umbones, and narrow posteriorly; 
anterior ends or auricles flattened in both valves, separated from 
the bodies of the valves by sharp declivities, the anterior margins 
below obliquely and sharply rounded; posterior ends or wings 
triangular, flattened, much larger in the left than the right valve, 
distinctly demarcated from the bodies of the valves, margins 
sharply emarginate, then swelling out to round the protuberant 
postero-ventral portions. Left umbo prominent, nearly central 
in position, the umbonal region abrupt on the anterior, but 
gently sloping on the posterior side to form a posterior slope ; 
umbonal cavity of the right valve containing a number of nodes 
(in the cast) indicating pits for muscular attachment ; adductor 
impressions and pallial scars not distinctly marked ; sculpture 
of the left valve consists of irregular concentric laminse and 
faint oblique radii, extending from the umbonal centre well on to 
the posterior end ; the surface of the right valve is transversely 
wrinkled on the cast. 
Obs. — The specimen is somewhat mutilated, but it presents 
most of the principal characters of the genus Limoptera , with the 
exception of the cardinal folds and the oblique posterior tooth. 
The former however may be hidden by the matrix infilling the 
deep ligamental recess beneath the umbones. The precise generic 
affinity of this shell, I am not at present prepared to give, but it 
accords better with Hall’s definition of Limoptera than with any 
other similar genus. It is more produced posteriorly than any of 
the shells figured by Hall under this name, and is also specifically 
distinct from any other yet described from New South Wales. 
The outward form only is that of some Glyptodesmce , or Pterinea 
as restricted, or even more so perhaps Leiopteria or Leptodesma , 
* It is impossible to unravel the mystery surrounding the first annunci- 
ation of many of the late Prof. James Hall’s genera. This reference is 
simply given as one to a description of the genus. 
