26 CAEBONIFEROUS LAMELLIBRANCHIATA. 



Craigen Glen; Beitb and Waterland, Ayrshire; Raven Crag, Teasses, and First 

 Limestone on shore east of Kinghorn, Fife ; West Quarry, Salton. 



Ohservations. — This species was estabhshed by R. Etheridge, jnn., for some very 

 small shells, which had a peculiar surface ornament. He lays stress on the specific 

 character of the smoothness of the umbonal region, and the freedom from radiating 

 ribs of the anterior end. I would add that the concentric lines of growth are more 

 strongly marked in this species than in others. PI. V, fig. 9, is a specimen of the 

 left valve, from Beitli, in the collection of Mr. J. Smith, of Kilwinning. This 

 is an uncrushed example, and shows the great comparative gibbosity of the valve. 

 Etheridge's type, a right valve, PL V, fig. 8, is probably flattened, but it may be 

 that the right valve was flatter than the left. 



Two slabs of specimens from Craigen Grlen, Campsie, are in the collection of the 

 Greological Survey, Jermyn Street. 



AcTiNOPTEEiA SULCATA, M'Coij, sp., 1844. Plate V, fig. 13. 



Pteeonites sulcatus, M'Coij, 1844. Syuops. Carb. Foss. Irelaucl, p. 82, pi. xiii, 



fig. 5. 

 _ _ Morris, 1854. Cat. Brit. Foss., 2nd edit., p. 181. 



— — Bigshy, 1878. Thesaurus Devonico-Carboniferus, p. 295. 



— — Etheridge, 1888. Brit. Foss., pt. 1, Palaeozoic, p. 277. 



Sjjecific Chdrdctcr.s. — Shell small, transversely triangular ; compressed anterior 

 cud; pointed umbones, small ; ornamented by several narrow radiating ribs. 



Locality. — Manor Hamilton, co. Leitrim, Ireland. 



Ohservations. — PI. V, fig. 13, is the type of M'Coy's P. sulcatas, and I quote the 

 species and figure the type for what it is worth. The shell is very imperfect, and 

 is very probabl}- a portion of a specimen of ^1. persidcata, M'Coy, sp. A specimen, 

 whose similar shape is entirely due to the incompleteness of the shell from Scotland, 

 is figured, PI. V, fig. 14, and I am quite of opinion that M'Coy founded his first 

 species on an imperfect specimen. 



Genus Posidonomya, Broun, 1837. 



PosiDONiA, Brcmn, 1828. Zeitscli. f. Miu., vol. i, p. 262. 

 Posidonomya, Bronn, 1835-7. Letli. Geogn., p. 88. 



Generic Description. — Shell of moderate size, ovate, oblique, compressed, with an 

 anterior rounded ear and a compressed expanded posterior ear. Hinge-line 



