108 CARBONIFEROUS LAMELLIBRANCHIATA. 



faunal relationship between the Culm and Pendleside Series. I have not met with 

 the species in the Lower Carboniferous Series. 



Pseudamusttim AUEICTJLATUM, M'Coy, sp., 1844. Plate XVI, figs. 23 — 27. 



Lima laevigata, M'Coy, 1844. Synops. Carb. Foss. Ireland, p. 88, pi. xiv, fig. 3 

 Inoceramxjs auriculatus, M'Coy, 1844. Ibid., p. 77, pi. xix, fig. 5. 

 Pecten cingendus, M'Coy, 1844. Ibid., p. 90, pi. xvii, fig. 11. 

 cf. Avicttlopecten ? concentrico-costatus, de Koninck, 188o. Ann. Mus. Koy. 



d'Hist. Nat. Belg., torn, xi, p. 237, 

 pi. xxxi, figs. 6, 7 ; pi. xli, figs. 

 28-33. 



Specific Characters.— Shell below medium size, inequivalve, the left valve 

 gibbose, the right valve less so; ovate, orbicular, oblique. The anterior margin 

 below the ear produced and rounded ; the lower margin broadly round ; the 

 posterior margin almost straight, making a right angle with the hinge-line, which 

 is straight and of medium length. The umbones gibbose, incurved, and pointed, 

 the left the higher, more swollen, and arching over the right. The anterior ear 

 well marked off from the valve, depressed and small, separated in the right valve 

 by the byssal slit ; the posterior ear large and ill-defined, its margin rectangular. 



Interior. — Unknown. 



Exterior. — The surface is smooth, but raised into several concentric ribs in 

 both valves, which become obsolete towards the posterior superior angle of the 

 valve. The ears seem to be smooth. 



Dimensions. — PI. XVI, fig. 25, a bivalved example in the collection of the 

 Geological Survey of Ireland, measures 



Antero-posteriorly . . . .10 mm. 



Dorso-ventrally . . . .18 mm. 



From side to side . . . .9 mm. 



Localities. — Ireland : the Carboniferous Limestone of Middleton and Little 

 Islmid, co. Cork; Abbeybay, Ballyshannon, co. Donegal; Croag and Knocksonna, 

 co. Limerick ; Millicent, Clane, co. Kildare. 



Observations. — The type of Inocera.mus auriculatus t M'Coy, is stated to have been 

 in the collection of Dr. Haines, of Cork, but I have not been able to trace it. Kelly 

 states that it came from co. Cork. 1 I have no hesitation in referring Pecten 

 cingendus, M'Coy, the type of which is in the Griffith Collection, Royal College 

 of Science Museum, Dublin, to this species. The latter is a right valve, evidently 



1 ' Journ. Geol. Soc. Dub.,' vol. vii, p. 12. 



