Kirkbya scotica, Jones & Kirkby.

Gunther, Albert C. L. G., Dallas, William S., Carruthers, William & Francis, William, 1885, The Annals and Magazine of Natural History, Including Zoology, Botany, and Geology, Reptiles and Batrachians from Brazil, LONGMANS, GREEN, AND CO.; SIMPKIN, MARSHALL, AND CO.; KENT AND CO.,; WHITT AKER AND CO.: BAILLIERE, PARIS: MACLACHLAN AND STEWART, EDINBURGH: HODGES, FOSTER, AND CO., DUBLIN: AND ASHER, BERLIN: TAYLOR AND FRANCIS, pp. 1-96 : 187-188

9. Kirkbya scotica, Jones & Kirkby.

(Pl. III. figs. 16 & 17.)

Kirkbya scotica, J. & K., 1867 , Trans. Geol. Soc. Glasgow, vol. ii. p. 220; 1871, vol. iii. Suppl. p. 28.

Kirkbya scotica, Armstrong and others, 1876, Catal. W.-Scot. Foss, p. 45.

Subrhomboidal, compressed, uniformly highest in the central third; height more than half the length. Dorsal border straight and over two thirds of the maximum length; ventral border slightly convex; extremities obliquely rounded, the posterior having the longest curve above, and the anterior below. Lateral contour (edge view) compressed-oblong. Subcentral pit roundish oval, and nearly in the centre of the valve in most cases. Valves covered with numerous (twelve or more) sinuous and inosculating ribs, somewhat concen ­ tric lengthwise and obliquely arranged. The ribs become less concentric and more parallel in some cases, as in fig. 17. Surface otherwise smooth, so far as known. Length inch. This species, which was discovered by Mr. James Thomson, of Glasgow, is allied to K. costata . It is about the smallest member of the genus; and it is rare, having as yet occurred only in two localities, both of which are north of the Border.

Localities.—Scotland. Carboniferous Limestone (Lower): Campbelltown, Argyleshire. Carboniferous Limestone (Upper): Linlithgow Bridge, Linlithgowshire.