48 BRITISH CARBONIFEROUS BRACHIOPODA. 



Spirifura mesogonia, M'Coy} Plate VII, fig. 24. 



Cystia mesogonia, M'Coy. Synopsis of the Carb. Fossils of Ireland, p. 137, pi. xxii, 



fig. 13, 1844. 

 Spibifek mesogonius, Be Koninck. Anirnaux Fossiles de la Belgique (supplement), 

 p. 660, pi. lvi, fig. 4, 1851. 



" Spec. Char. Semicircular, gibbous : surface smooth ; cardinal area wide, concave, 

 triangular ; cardinal angles acute ; mesial ridge very prominent, angular, both it and the 

 angular mesial furrow without ribs ; eight or nine strong rounded equal ribs on each side 

 of the mesial fold. 



" This species is allied to Spirifer distans, Sow., and Sp. ostiolata, Phillips, but is 

 distinguished from both by the very prominent, angular mesial fold; Sp. distans has 

 also the mesial hollow ribbed, while it is smooth in the present species. 



" Length 1 inch, width 1 inch 5 lines." 



Obs. Professor M'Coy's figure represents a shell having about twenty-two ribs on each 

 valve and a smooth mesial fold, while Professor De Koninck's illustration of what he 

 considers to belong to the same species from Belgium would only possess about fourteen, 

 these being likewise much wider proportionately to the mesial fold than those of Professor 

 M'Coy's example. I cannot, therefore, positively affirm that both did belong to the same 

 species, although such in reality may have been the case. 



Loc. Mr. Kelly mentions Millecent and Hook as the Irish localities. M. De Koninck 

 found it at Chokier, in Belgium, where it is stated to be very rare. 



Spirifera subconica, Martin. Plate IX, fig. 3. 



Conchyliolithus subcontcus, Martin. Petrefacta Derbiensia, tab. xlvii, figs. 6 — 8, 



1809. 



Spec. Char. Wider than long; dorsal valve semicircular; ventral, sub-pyramidal; 

 hinge-line straight, as long as the greatest width of the shell ; area large, triangular ; fissure 

 of moderate width. The smaller valve possesses an angular mesial fold, with correspond- 

 ing sinus in the opposite one. Both valves are ornamented by about sixteen angular ribs. 



Length 14, width 18, depth 11 lines. 



1 Not having had the opportunity of examining any example of this species, and as the original is no 

 longer to be found in Dr. Griffith's collection, all that can be done is to reproduce the author's description 

 and figure. 





