19 
Tliose specimens figured on PL IX, Pigs. 10, 11, and PL XIV, Pigs. G, 
7, 8, may be taken to represent an obese form of this species, which appears 
to be characteristic of the Lower Marine Series. 
AVe name this species in honour of Mr. B. G. Englehardt, of the 
Department of Public Instruction, a well-known and diligent collector of 
Permo-Carboniferous fossils in the IllaAvarra District, to whom we are indebted 
for many valuable additions to the fauna of that period. 
Localities and Horizons. — Cabbage-tree Point, Plat Bock Creek, near 
Xowra {C. Cullen) ; Eailway Cutting, AA^ollongong (C^ Cullen)-, A\’’ollongong 
(./. IVaterhouse) ; near AA^est Alaitland [J, Waterhouse) ; AVollombi Eoad (</. 
Waterhouse) ; Eed Eock, near Drake {E. C. Andrews) ; Brauxton. — Permo- 
Carboniferous — Upper Marine Series. AI.P. 5, Parish Heddon (C. Cullen) ; 
? Parley (./. JVaterhouse) ; ALP. 2, Parish Ileddon (C. Cullen). — Permo- 
Carboniferous — Lower Marine Series. 
Collection. — Alining and Geological Aluseum. 
Aviculopecten ptychotis, McCoy, sp. 
(Plate XV, 5-7.) 
Lecten J^tychotis, McCoy, Ann. Mag. Nat. Hist., 1847, XX, p. 298, t. 14, f. 2. 
Observations. — A small, orbicular, and subequilateral shell, with gently 
convex valves, the right exhibiting a narrow, transversely-elougate anterior 
auricle, rounded on its outer margin, and radiate in the adult, square-ended 
and plicate in the young, separated from the body of the valve by a deep and 
narrow byssal sinus; the posterior auricle is rectangular, small, and 
inconspicuous. Both auricles of the left valve are similar to the posterior of 
the right. It is — 
1. Aviculopecten depilis, De Koninck^ (non AlcCoy'). — This specimen 
was a right valve, the auricles “ striated,” the anterior separated off hy a 
straight and well pronounced sinus, the posterior smaller and rectangular. 
2. Aviculopecten Laurienti, Eth. fil.^ — It was formerly pointed out 
by one of us that the shell figured by De Koniuck as A. depilis could hardly 
be that of the same name by AIcCoy, and the name A. Laurienti proposed 
for it. At the same time an error was committed by uniting with the valve 
resembling De Koninck’s figure, a costate specimen as the opposite valve. 
. • De Koninck — Recb. Foss. Pal. NouT.-Galles du Sud, Pt. 3, 1877, p. 15-4-, t. 22, f. 7. 
“ McCoy — Synop. Carb. Lime. Foss. Ireland, 1844, p. 91, t. 16, f. 11. 
* Etheridge, Junr.— Geol. Pal. Q’land, &c., 1892, p. 268, t. 43, f. 3 (non 4.) 
