149 
interesting, as it gives exactly an almost complete mould of the internal 
surface of this valve. It is easily seen from the figure that the shape of this 
specimen is transversely suhoval, and decidedly broader than long. One can 
see in it, distinctly, superficial traces of the concentric lines of growth, and 
of numerous small spines which cover the external surface of this species, 
forming, indeed, its most important characteristic. The impressions of the 
adductor muscles are also very correctly represented ; they are relatively small, 
shallow, elongated, and dendritic towards their upper end. The reniform 
impressions are entirely absent ; the median plate, serving to strengthen and 
support the cardinal process, is relatively thin, but occupies nearly two-thirds 
of the length of the valve. The cardinal process is strong and trilobed. It 
must be noted that on the ears and surrounding parts traces of concentric 
rings are completely effaced, and in their place is a subtriangular surface 
covered with minute granulations ; this probably proves that the shell was 
thicker here than in the rest of the valve, the traces of ornamentation being 
more completely effaced. 
Dimensions . — The length of the specimen here described is about four 
centimetres, and its breadth 5’5 centimetres. 
Dorizon and Localities . — This species is very abundant in the up 2 oer 
beds of the Carboniferous Limestone, less frequent in the middle beds, and 
aj^parently absent in the lower beds. This is probably why it is so rare in the 
Carboniferous rocks of America, where the lower beds are much better 
rej)resented and more developed than elsewhere. It was found, for the first 
time in Australia, by the Lev. W. B. Clarke, in a brown phtanite at Buchan, 
on the banks of the Gloucester Liver, and in a grey limestone on the banks 
of the Kama and Williams Livers. 
Productus pimbriatus, Sowerby.^ 
PL XI, Pig. 5. 
Froductus finihriatus, j. de Carle Sowerby, 1823, Min. Conch., V, p. 85, pi. 459, fig. 1. 
,, ,, L.-Gr. de Koninck, 1847, Eech. Anim. Poss., I, p. 127, pi. 12, fig. 3, 
„ „ Qnenstedt, 1852, Handb. Petrefaktenkunde, p. 491. 
,, ,, Davidson, 1861, Mon. Brit. Carb. Brack., p. 171, pi. 33, fig. 12 and 
13, and pi. 44, fig. 15. 
„ ,, L.-G. de Koninck, 1873, Eech. Anim. Poss., II, p. 32, pi. 1, fig. 18. 
' [Prodwhis cf. Jimhriatus. 
W.S.D.] 
R. Etheridge, Junr., Geol. and Pal. Q’land., 1892, p. 255, t. 12, f. 15. — 
