230 
than at the beaks. These folds are not very regular, esjDecially towards their 
extremities, where they are divided by wider furrows than at their origin ; 
they are crossed by some concentric undulations of growth. 
Dimensions . — The length is about thirteen, breadth fifteen, and 
thickness four centimetres. 
Delations and Differences. — This species differs from the preceding by 
the obliquity of its hinge line, and the simplicity of its radiating folds. 
Horizon and Localities. — This species was first found by Strzelecki in 
the Eastern Marshes of Tasmania, and by Mr. Eaintree in the Carboniferous 
rocks of Gympie, Queensland. Mr. W. B. Clarke found two large specimens, 
one in the Muree Sandstone, and the other in the Wollongong sandstone. 
This last I have figured. 
Aviculopecten consimilis, F. McCoy. 
PI. XXII, Pig. 6. 
Fecten consimilis, P. McCoy, 1841, Synop. Carb. Poss. Ireland, p. 91, pi. 15, fig. 16. 
This shell is small, oval, slightly convex, with an entirely smooth 
surface. Its ears are rather small and unequal, the anterior ear is the largest, 
rounded at its extremity, and distinctly separated from the rest of the shell 
by a linear sinus ; its surface is strongly reticulated, while the surface of the 
posterior ear is nearly smooth, and its extremity rectangular. 
Dimensions. — The length is fifteen, and the breadth thirteen millimetres. 
Delations and Differences. — This species is easily distinguished from 
A. orhiculatus, McCoy, by its more oval form, but chiefly by the reticulated 
design on its anterior ear. 
Horizon and Localities. — In Ireland it occurs at Bundoran. A single 
specimen of it was found in a brownish argillaceous limestone at Burragood. 
Aviculopecten depilis, F. Me Coy. 
PI. XXII, Pig. 7. 
Fecten depilis, P. McCoy, 1844, Synop. Carb. Poas. Ireland, p. 91, pi. 16, fig. 11. 
This is a small, orbicular, subequilateral, slightly ventricose shell, 
either with a smooth surface, or simply ornamented with slight concentric 
^ [Aviculopecten Laurienti (i), R. Etheridge, Junr., Geol. and Pal. Qlaiid., 1892, p. 268, t. 43, f. 314. — 
