21 
latter ; we doubt it. At any rate, De Koninck’s illustration represents a very 
inequilateral valve, devoid of auricles, inflated in the nmbonal region, and 
extended backwards into a somewhat flattened posterior end. The eostae 
are alternately larger and smaller, the former granular, the latter interpolated 
hetAveen the larger, and, apparently, undecorated. The cliaraeters displayed 
hv our speeimen arc precisely similar. To ascribe a name to this slicll, Avitli 
our limited knoAAdedge of it, is quite out of the question. 
Loculilij and Horizon. — Hills to the Avest of Mount Uriari, Parish 
Somerfon, County Pari'y (C. Cullen). -Carboniferous. 
Colleclion. — Mining and Geological Museum. 
Aa ICULOrECTEX TESSELLATUS, FhUlipS, Sp. 
(Plato XV, Figs. 8 and 9.) 
AlHCllla tessellala, Phillips, 111. Geol. York., 18;16, p. 211, t. G, f. G. 
Aviculopecten tessellatus, Morris, Cat. Brit. Foss., 2nd cd., 18D4, ]). IGG. 
AvtCula tessellala , Eth. fil., Geol. Mag., 1879, VI (2), p. 161 {Gilbertson t>/pe). 
Observations . — In the identity of this shell AA’e are in accord AA'itli 
Professor Do Koninck, for, Avith the material at our disposal, aa^o arc quite 
unable to distinguish our s]Aecimeus from Phillips’ Avicida tessellala. It is — 
Aviculopecten tessellatus. Do Kou.^ — The latter described Ijotli valves, 
the right being someAA'hat more convex than the left, tAA^elve to fifteen 
equidistant costm, Avith concentric latilaminao, producing between them a 
tessellation of the surface. The anterior auricles arc nearly rectangnlar, and 
only sejiarated from the bodies of the valves by shalloAV grooves, that on the 
right valve divided off by a feeble emargination. The posterior auricles are 
much larger than the anterior, flattened, and terminating at the posterior 
lateral angles in acute points ; the edges thence emarginate to the SAvell of 
the posterior ventral margins. 
Our specimens, both left valves, accord in eveiy })articiilar with 
De Koninck’s description. lYe may add that the costae on the jiosterior 
margins (the ventral and anterior arc not fully preseiwedl terminaf e outAvardly 
^ De Koninck — Eecb. Eos.?. Pal. Xour.-Galles clu Slid, Pt. 3, 1877, p. IGO, t. 22, f. 11. 
