182 Messrs. Jones and Kirkby on the 



of St. Monans, Fifeshire. Carboniferous Limestone (Upper) : 

 near Kinneil Mill and Orchard Quarry. 



Under this name (K. oblonga) we also place certain speci- 

 mens that occurred to us first from the Carboniferous-Lime- 

 stone series of Fife (figs. 4 and 6). The character of their 

 reticulated surface, central pit, and ventral riblets sufficiently 

 identify them with Kirkbya. We describe them thus : — 



Varying from subreniform to suboblong and subquadrate 

 in outline, often compressed ; height two thirds of the 

 length. Dorsal border straight for from about a third to a 

 fourth less than the maximum length ; ventral border curved 

 or straight in central third ; extremities rounded, the anterior 

 being slightly the more acute. Surface reticulated (hexagonal 

 or pentagonal meshes) and with two or more faint concentric 

 riblets (including a slight marginal rim) below. Length 

 ^V inch. Edge view (lateral contour, fig. 6 b) is acute-oval. 



Discovered by Mr. James Bennie in the Lower-Carbon- 

 iferous Limestone, on the coast near Seafield Tower, Fifeshire. 



Figs. 5 a, 5 b, represent a form that Mr. Robertson has 

 from Williamswood, near Glasgow. It is relatively shorter 

 than K. permiana, and the dorsal line is only about two thirds 

 of the total length ; it is thus nearly oblong, with rounded 

 ends. The valves have each a slight marginal rim, are 

 humpy towards the ends, or faintly lobed, and more coarsely 

 reticulated than is usual with K. permiana ; and there is a 

 weak submedial riblet in some individuals. We figure it so 

 as to keep it in view, as it is a form requiring further study. 

 A somewhat similar short form, but more convex and more 

 definitely ridged, we have seen in Mr. C. Moore's collection 

 from Steeraway, Salop. Probably they are all closely allied 

 to K. oblonga. 



4. Kirkbya annectens, Jones & Kirkby. (PL III. figs. 7, a-d ; 

 and var. bipartita, figs. 8, a, b.) 



Kirkbya annectens, J. & K., 18GG, Ann. & Mag. Nat. Hist. ser. 3, vol. 



xviii. p. 42. 

 Kirkbya annectens, J. & K., 1867, Trans. Geol. Soc. Glasgow, vol. ii. 



p. 220 ; and bipartita, 1871, vol. iii. Suppl. p. 28. 

 Kirkbya annectens and K. bipartita, Armstrong and others, 187G, Catal. 



W.-Scot. Foss. p. 44. 



Valves suboblong in outline, rather convex and lobed, 

 height half the length or more. Dorsal border straight or 

 slightly incurved, and about two thirds of the maximum 

 length ; ventral border either straight or slightly incurved, or 

 as slightly convex ; extremities rounded and in some speci- 

 mens nearly alike, in others the anterior is the more acute. 



