244 
SUPPLEMENT TO THE BRITISH 
From this Lower magnesian limestone Mr. Kirkby enumerates the occurrence of three 
species of Brachiopoda, and of these I have seen specimens, namely : 
1. Spirifera ?7m', comparatively common, but always in detached valves, and he states 
that he has seen this species fully iiiths of an inch in width. 
2. CamaropJioria critmena, which appears to be rare, since he got only a single 
fragment of the shell, but quite sufficient to identify it. 
3. Of Chonetes a species, which he did not name, but has subsequently identified with 
the Chonetes Damdsoni of Baron Von Schauroth, and of which I will now append a 
description. 
Genus, Chonetes, Fischer. 
1. Chonetes DavidsonI, Schauroth. Sup., PI. XXX, figs. I, 2. 
Chonetes Daviusoni, Schauroth. Zeitschr. d. Deutschen Geologischen Gresellschaft 
Jahrg., 1856, p. 222, pi. xi, fig. 1, 1856. 
— sp. ? Dav. Carb. Mon., p. 279, 1863. 
— — J. Kirkby. Trans. Tyneside Naturalists' Club, 1864. 
Shell marginally semicircular, and either as long as broad, or broader than long. 
Valves concavo-convex. Hinge-line straight, and nearly as long as the breadth of shell. 
Cardinal extremities angular. Dorsal valve concave, flattened near and at cardinal angles ; 
hinge-area narrow. Ventral valve convex, also flattened at and close to cardinal angles. 
Area triangular, divided in the middle by a fissure, partly arched over by a pseudo- 
deltidium. Along the cardinal edge, on either side of the beak, a row of three or 
four delicate, hollow, tubular spines, becoming gradually longer as they recede from 
the extremity of the beak, and diverging obliquely from the cardinal edge. Surface 
marked with numerous radiating striae, crossed by concentric lines of growth. 
Length 5, width 6 lines. 
Obs. — In 1856 both Mr. Kirkby and myself felt embarrassed as to the identification 
of some indifferently preserved specimens of this species, and Mr. Kirkby could not 
perceive in his specimens the radiating striae which usually characterise shells of this 
genus. The subsequent discovery of perfect examples showed these radiating striae, and 
it has appeared to both Mr. Kirkby and myself that, although larger, it may in all proba- 
bility be referable to the Chonetes Davidsoni of Baron Schauroth. In some of the English 
specimens the hollow spines were of comparatively great length, some of them being 
nearly as long as half the length of the shell. It is not the Chonetes Hardrensis, as I at 
one time thought it might be ; and Prof. L. de Koninck is of opinion that the Devonian 
species does not occur in the Carboniferous rocks of Great Britain, and that the shell 
attributed to it is his Chonetes Lagiiessiana. 
