PSEUDAMUSIUM ELLIPTICUM. L03 



Pseudamusium ellipticum, Phillips, sp., 1836. Plate XX, figs. 11 — 18. 



Pecten ellipticus, Phillips, 1836. Geol. Torks., pt. ii, p. 212, pi. vi, fig. 15. 

 M'Goy, 1844. Synops. Carb. Foss. Ireland, p. 92. 

 — elongates, M'Coy, 1844. Ibid., p. 92, pi. xvi, fig. 9. 

 depilis, M'Coy, 1844. Ibid., p. 91, pi. xvi, fig. 11. 

 eilatus, M'Coy, 1844. Ibid., p. 93, pi. xiv, fig. 10. 



ellipticus, de Verneuil, 1845. Geol. Russie de l'Europe, p. 329, pi. wi, 

 fig. 8. 

 Aviculopecten ellipticus, Morris, 1854. Cat. Brit. Foss., 2nd edit., p. 164. 

 Pecten elongatus, de Koninch, 1877. Recherches Foss. Pal. New South Wales, 



p. 155, pi. xxii, fig. 5. 

 Streblopteeia elongata, de Koninch, 1885. Ami. Mus. Roy. d'Hist. Nat. Bel"., 



torn, xi, p. 205, pi. xxxii, fig. 8. 



Specific Characters. — Longitudinally ovate, below medium size, moderately 

 and regularly convex. The margin one unbroken curve from ear to ear. Hinge- 

 line small and straight. Anterior ears small, triangular, depressed, that of the 

 right valve separated from the margin of the valve by a deep groove. Posterior 

 ears small, triangular, depressed. Umbones pointed, central, moderately swollen. 



Interior. — The hinge-plate is triangularly elongate, smooth (only the anterior 

 third has been seen). Adductor muscle-scar normal. 



Exterior. — The surface, including the ears, is smooth. Occasionally concentric 

 striae or irregularities of growth are seen, and some examples have obscure, 

 radiating, obsolete ribs, especially near the anterior margin, often marked with 

 radiating colour-bands on the left valve. 



Dimensions. — PI. XX, fig. 13, the type of Phillips's Pecten ellipticus, measures — 

 Antero-posteriorly . . . .2-5 mm. 



Dorso-ventrally . . . .31 mm. 



Localities. — England : the Carboniferous Limestone of Thorpe Cloud, Park Hill, 

 and Castleton, Derbyshire ; Narrowdale, North Staffordshire ; Hill Bolton, York- 

 shire. Scotland : the Upper Limestone series of Bowertrapping; Grenwhappleburn, 

 Craigenglen. Ireland : the Carboniferous Limestone of Rathkeale, Askeaton, and 

 Curraghbeg, co. Limerick ; Little Island, co. Cork ; Townplots, Killala, co. Mayo ; 

 Millicent, co. Kildare. 



Observation*. — The type of Pecten ellipticus, Phillips, is preserved in the 

 Grilbertson Collection, Natural History Museum, South Kensington, and I figure it 

 in PI. XX, fig. 13. It is a left valve, imperfect in front, and shows the short ears 

 and general contour of the valve. It does not show, however, the radiating lines 

 and colour-bands so commonly found in examples of this species. The type is 

 rather more elliptical than most of the specimens I have studied, and perhaps for 



