CARBONICOLA ANGULATA. 75 



Moss Coal, N. -Staff. Field; Blue Flats, Coalbrookdale ; Bradford; Grains Iron- 

 stone ; Brooch Ironstone ; Gubbin Measures, Foxyard ; Dudley, S. Staffs ; 

 Radstock ;* Whitley, shale above Lower Main Coal, and Newbiggin ; Cannock 

 Chase ; Netherton, near Morpeth, above high main seam ; Horsley Wood, Wylam ; 

 17 feet below Bensham seam; 5 feet 4 inches seam, Heworth ; Beaumont seam, 

 Newcastle-on-Tyne ; roof of Shale Coal, Stanley Main, Wakefield ; New Mine, 

 Bardsley ; Stubbs's Mine. Wales : S. Wales, over Four-foot, Hafod ; Sychffos ; 

 Ynys Cedwin, from the Pennypieces ; Bagillt, Hollywell, Flintshire. Many of these 

 localities are copied from labels of specimens in the Museum of the Geological 

 Survey, Jermyn Street. Scotland: Mussel-band, Kilbride; U. C. M., Fullerton, 

 Ayrshire ; Eight-foot Coal, Scoonie, Fife. 



13. Caebonicola angulata {de Ryckholt). Plate XI, figs. 3 — 5. 



Caedinia angulata, de Ryckholt. 1850, p. 104, part i, pi. vi, figs. 10 and 11. 

 Anodonta angulata, Ludvng. Pal. Urals, 1863, band x, pi. iii, figs. 9, 9 a. 

 Naiabites angulata, Dawson. Acadian Geology, 2nd edit., 1868, p. 243, fig. 46. 

 Caebonicola angulata, Hind. Quart. Journ. Geol. Soc, 1894, p. 441, pi. xx, 



fig. 14. 



Specific Characters. — Shell transverse, small ; anterior end rounded, moderately 

 tumid, consisting of about one-third of the shell. The posterior end is obliquely 

 truncate from above downwards, with the upper angle obtuse, and the inferior 

 one rather less than a right angle. The inferior border is almost straight. 



The umbones are small, elongate, with their apices pointing slightly forwards, 

 contiguous, and prolonged backwards and downwards in an angular ridge, which 

 terminates in the posterior inferior angle of the shell. They rise in front by a 

 gradual tumidity, concave upwards, commencing at the anterior margin of the shell. 

 The valves are compressed and flattened into the superior and posterior borders 

 above the oblique ridge. Surface marked with fine strias and lines of growth. 



Interiors. — Normal ; but no specimens showing the hinge have been met with. 



1 This is the only specimen of molluscan remains which I have seen from the Eadstock Coal- 

 measures, and is in the possession of Mr. E. Kidston, of Sterling. It occurs on a piece of shale with 

 plant remains from the Upper Coal-measures of Eadstock. At p. 36 of the ' Memoirs Geol. 

 Survey Great Britain,' " The Geology of the East Somerset and Bristol Coal-fields," 1876, is a 

 notice of the occurrence of " casts of bivalve mollusca (Anthracoptera ?) in the coal-shale at 

 Twerton, on the authority of Prof. Morris ; and of " Anthracosia ? " at Cammerton on the authority 

 of Mr. McMurtrie. Owing to the high position of the beds of this Coal-field, which, according to 

 Mr. Kidston, are the highest in England, the paucity of molluscan remains points to a change in 

 the conditions of deposition from that which obtained in the period of the Middle Coal-measures. 



