84 CARBONIFEROUS LAMELLIBRANCHIATA. 



figure of this specimen seems to lie the only one which was reversed on the stone 

 and consequently shows correctly on the plate. This does not excuse the author 

 of the description of the species in de Koninck's work for the statement that "the 

 right valve is unknown." Mr. J. Wright has a series of four specimens in his 

 collection from Little Island, co. Cork, two of which are right and two left valves. 



Pect&n Hardingii, M'Coy, judging from the figure, is probably the same species, 

 but the type has disappeared, and it is impossible to say what the original may 

 have been. 



Aviculopecten macbotis, M'Coy, sp., 1844. Plate XVIII, figs. 15 — 18. 



Pecten maceotis, M'Coy, 1844. Synops. Cavb. Foss. Ireland, p. 96, pi. xvi, fig. 13. 



Specific Characters. — Shell small, only moderately convex, transverse diameter 

 rather large compared with the size of the shell. The anterior border short, 

 descending obliquely downward and forward ; the lower border broad and convex ; 

 the posterior border descending obliquely from the umbo backwards and downwards 

 and nearly straight. The hinge-line long and produced above the upper border of 

 each ear. The umbones small and pointed. The ears large, well defined, and 

 depressed, with the margins of both falcate. 



Interior. — Unknown . 



Exterior. — The surface is ornamented with numerous fine ribs. The ears are 

 almost smooth, but have delicate concentric lines of growth. 



Dimensions. — PI. XVIII, fig. 1G, measures — 



Antero-posteriorly . . . .17 mm. 



Dorso-ventrally . . . .13 mm. 



Localities. — Ireland : the Carboniferous Limestone of Little Island, co. Cork ; 

 Bruckless, Dunkineely, co. Donegal. 



Observations. — It is uncertain whether this species is not the very young stage 

 of A. fallax. I have found six specimens in the cabinet of Mr. J. Wright which 

 appear to be about the size of the type (PI. XVIII, fig. 18). The type is 

 preserved in the Griffith Collection, Museum of Science and Art, Dublin, and is a 

 right valve. 



Aviculopecten Knockonniensts, M'Coy, sp., 1844. Plate XIV, figs. 8 — 13. 



Pecten Knockonniensis, M'Coy, 1844. Synops. Carb. Foss. Ireland, p. 95, 



pi. xvii, fig. 4. 

 Cf. — bellis, M'Coy, 1844. Ibid., p. 89, pi. xv, fig. 15. 

 Aviculopecten pera, M'Coy, 1855, Brit. Pal. Foss., p. 488. 



