20 
an immense number of elose concentric frills, which also (lecussatc the 
quadrangular auricle of the convex valve. Part of a broad striated hinge- 
l)late is visible in one specimen, and a sub-deltoid chondrophore in another. 
Im])erfect as this description is, it is all we can ascribe to our concep- 
tion of “ Vecleti Illmvarensis,'' IMorris. As previously foreshadowed, we 
cannot include De Koniuck’s fmurcs within our svnonomv, for two reasons — 
lirst, the latter do not represent an orbicular, but rather an elongately-orbicular 
shell ; and, secondly, the costec are not sufTiciently numerous. The same 
remarks apply to Dana’s figure also. At the same time, in justice to 
De Koninck, it must be admitted that his description accords far better with 
our conceived “ Fccten illawarensi'i'' i\\^w do his illustrations. The whole 
question of the identity of Morris’ species is a very intricate one, and we do 
not bv anv means feel convinced that Ave have solved it satisfactorilv. 
Localities and Horizon. — Harper’s Hill; Allandale {C. Cnlle7i) ; 
Mt. Britton Gold-licld, Queensland ( Z?. L. Jack ). — Permo-Carboniferous — 
Lower Marine Series. 
Collections. — Mining and Gcolo!?ical Museum, and Australian Museum. 
Deltopecten suequixqeelineatus, McCoy, sq. 
(Plate HI, Fig. 2; PI. IX, Figs. 1-5; PI. XII, Figs. 2 aiul 3; PI. XIII, Figs. 2 and 8; 
PI. XIV, Fig. 1.) 
Feclen suhquinquelinealns, McCoy, Ann. i\Iag. Xat. Hist., 1847, XX, p. 398, t. 17, f. 1. 
Ohservalions . — McCoy’s figure represents the nearly perfect left valve 
of Avhat we take to be the typical form of this species — a “ truncate orbicular,” 
equilateral shell tvith large auricles. Variation takes place in ttvo directions, 
viz., slightly in the outline, and extensively in the nature of the costas. It is 
necessary to bear in mind that this typical form possessed tAA'cnty-five primary 
costae, an equal numher of secondary, and double the number of tertiary. The 
characters given below may be regarded as supplementary to those of IMcCoy. 
It is the : — 
1. Fecten coniplus, Dana^ {non McCoy^). — Dana describes only one 
valve — the convex or left. It is said to he sidiorbicular, Avith from tAventy to 
twenty-tAVo primary costm, and one or two in each of the intercostal spaces ; 
the auricles are longitudinally striate. 
' Dana — Am. Journ. Sci., 1817, 1 1 (4), p. IGO ; AVilkes U. S. Explor. Exped., 18U), X (Qeol.), p. 701, t. 0, f. 5, 
^ AJeCoy — Synoji. Garb. Lime. Foss. Ireland, 1814, p. 40, (. 15, f. 14, 
