152 B. Etheridge^ Jun. — On Carhoniferous Mollusca, 



of this species, its true generic affinities will remain doubtful. If I 

 am correct in regarding the obliquity as anterior, then the deeply 

 defined anterior ear, short hinge line, and prominent antero-ventral 

 outline would indicate Streplopteria, McCoy, as the proper genus, 

 although I am aware that the posterior ear or wing in the latter is 

 described as wide and undefined, whereas in the present species it is 

 small, again another feature which separates it from Aviculopeden. 

 Of the two, Strejplopteria at present appears to have the strongest 

 claim, at any rate until the internal characters of the hinge can be 

 determined. The radiating brown bands representing the original 

 colour markings vary considerably in A. ? suhlohatus. On one speci- 

 men there are as few as six or seven, on another as many as four- 

 teen or fifteen, passing straight from the beak to the margin, or be- 

 coming slightly flexuous in their course. They are also of variable 

 thickness, those near the centre of the shell being the thickest, 

 gradually decreasing to the sides, and separated by intervals of vary- 

 ing breadth on the same shell. They exist as plain bands, or each 

 one bifurcates, or each alternate one bifurcates, or, as in one solitary 

 example, the three central out of the seven bands are split up into 

 three thinner subdivisions, uniting towards the beak. Occasionally 

 smaller bands are interpolated between the larger, extending and 

 becoming thinner upwards towards the beak, from the margin, but 

 not reaching the former. 



Log. — Longnor, Derbyshire. Coll. Mus. Pract. GeoL, London ; and 

 British Museum. 



Amculopeden papyraceus, Sowerby. Plate YI. Fig. 7. 



Fecten papyraceus, Min. Con. vol. iv. p. 75, t. 3/54. 



Avicula papyracea^ Goldfuss; Petrefacta, 1834-40, vol. ii. p. 126, t. 116, f. 5. 

 Pecten papyraceus, Phillips ; Geol. York. 1836, vol. ii. p. 213. 

 ?» „ Prestwicli; Trans. Geol. Soc, 1840, 2nd ser. vol. v. p. 491 



(without description). 

 Avicula papyracea, de Koninck; Anini. Foss.Ter. Carb.Belg"., 1842-44,p. 136,t.5,f.6. 

 „ „ Morris; Cat. Erit. Foss., 1843, p. 107 (without description). 



), „ Tennant; Strat. List Brit. Foss., 1847, p. 101 (without description). 



jj J, Bronn; Index Pal. Nomen., 1848, p. 140 (without description). 



)> }> D'Orhigny; Prodi-ome de Pal., 1849, vol. i. p. 137 (without 



description) . 

 Pecten papyraceus, Brown; Foss. Conch., 1849, p. 159, t. 61**, f. 11. 

 Avicula teauissima, ,, ,, ,, ^^ 



„ tenera, „ „ „ p. 163, t. 61**, f. 11. 



Aviculopeden papyraceus, McCoy; Brit. Pal. Foss., p. 488. 



jj 55 Morris; Cat. Brit. Foss., 1854, 2nd ed. p. 165 (without 



description). 

 „ 55 Salter; Mems. GeoL Surv., Geol. Oldham, 1864, t. 1, f. 1 



(without description). 

 55 55 Huxley and Etheridge ; Cat. Foss. Mus. Pract. Geol., 1865, 



p. 159 (without description). 

 „ „ Armstrong and Young's Cat. Foss. "W. Scot., Trans. Geol. Soc. 



Glasgow, vol. iii. Supp. 1871, p. 47. 

 » 55 I^aily; Hull's Coal Fields, 1873, frontispiece, f. 2 (without 



description). 

 55 ,5 Baily; Char. Foss., 1875, vol. i. part 4, p. 113, t. 39, f. 1. 



Sp. Chars. — Semicircular, truncated by the hinge line, oblique 



