181 
from S. glaber by its shallower valves, its much sharper margin, by the 
slighter curvature of its beak, and, above all, by its large lateral folds. 
I do not deny that some specimens of S. glaher have also lateral folds, but 
when these exist they are always very superficial, thinner and much more 
numerous than in S. Darwinii. Mr. Dana has confounded this species with 
the S. Hawlmisii, J. Morris and D. Sharpe, which latter is Devonian, and 
which also is easily distinguished by the length of its area, which occupies 
the greatest diameter of its shell, and^by its angular ears. 
Horizon and Localities . — This species ajopears common in New 
South Wales. Mr. J. Morris says there are large casts of it found in a 
Carboniferous sandstone at Glendon. Mr. McCoy says it is common in the 
arenaceous shales of Loder’s Creek and Barraba, but rather rare in the 
arenaceous limestones of Black Head. The Bev. W. B. Clarke collected a 
large number of casts in Muree Quarry, in different railway cuttings between 
Maitland and Stony Creek, at Mount Whngen, and Harper’s Hill. The small 
specimen, like that which has 1)een figured by Mr. J. Morris, and which I 
have rej)resented in PI. X, Pig. 11, comes from Harper’s Hill. Only one 
specimen has preserved a large piece of its shell. This shell is very fibrous 
in great part of its length, but shows in places the remains of granulations 
which ornament the surface of young individuals, and so leaves no doubt as 
to the determination of the species. (PI. X, Pig. 11.) 
Spiriper ovipormis, F. McCoy} 
PI. XII, Pig. 8. 
Spirifer oviforniis, McCoy, 1847, A.nn. Mag. Nat. Hist., XX, p. 234, pi. 43, fig. 5, 6. 
This shell is nearly as long as broad, snbtrigonal when well preserved, 
with valves of equal depth, having their greatest diameter towards the lower 
third of their length. The ventral valve has a broad deep furrow, on each 
side of which are two or three radiating lateral folds, rounded, and separated 
from each other by furrows of the same breadth. The hinge area should be 
narrow and occupy only about one-third of the breadth, of the shell. The 
dorsal ridge is very large, and has a longitudinal furrow down its centre, 
beginning at the beak and extending evenly to the base. The numerous 
internal casts I have examined show that the muscular impressions of the 
* {Martiniopsis oviformis, McCoy. — W.S.D.] 
