50 BRITISH CARBONIFEROUS BRACHIOPODA. 



tion -^ but the figure is uot sufficiently precise to warrant a decided assertion, and for which 

 reason I have retained the name subsequently introduced by Professor Phillips. In his 

 work on the ' British Palaeozoic J'ossils,' p. 428, Professor M'Coy justly observes that 

 Sj). rotundata, of Martin, is quite distinct from Sp. rotundata, Sow. ; but is decidedly in 

 error while considering Sp. planata, of Phillips, a synonym of Martin's species, for a 

 comparison, however slight, of the last-named shell (PI. VII, figs. 28—36) with that of 

 Martin, of which I have reproduced the original illustration (PL IX, fig. 27), will, I 

 believe, convince any one of the greater probability of Martin's shell being that of a young 

 specimen of Sp. integricosta, because, besides a difference in its general shape, the ribs of 

 Sp. plannta are always proportionately smaller and more numerous than in Martin's figure. 

 Spirifera paucicostata, M'Coy,^ of which I have reproduced the original drawings (PI. IV, 

 fig. 12), is, perhaps a variety of Sp. integricosta, but not of Sp.pinguis, as was erroneously 

 printed in the description facing PI. IV of the present monograph. The ribs on the mesial 

 fold, as well as the general shape of the shell, are more those of Phillips's than of Sowerby's 

 species. Sp. integricosta is not a very common species in the carboniferous limestone ; 

 it occurs at BoUand, in the Craven district, Northumberland, &c. It was also collected 

 in the Isle of Man by the Rev. Mr. Cumming. In Ireland Mr. Kelly mentions Bundoran, 

 Millecent, and Little Island. In Scotland it has been found at Gare, in Lanarkshire. 



Spirifera fusiformis, Phillips. PI. XIII, fig. 15. 



Spirifera. fusiformis, Phillips. Geol. of Yorkshire, vol. ii, p. 217, pi. ix, figs. 10, 11, 



1836. 



Spec. Char. Fusiform, about three times as wide as long, the beak and umbone 



tribe. Valves longitudinally furrowed; margin obtusely crenate, with a scarcely distinguishable sinus. 

 The beak of the larger valve incurved. A small and not a very common species. Limestone, Middleton. 



' Professor De Koninck informs me that he is now of the same opinion. 



2 Professor M'Coy describes his species as follows : 



"Spec. Char. Globose, or very broad-ovate; hinge line slightly shorter than the width of the shell ; 

 cardinal angles slightly obtuse, sides and front moderately rounded, very obtuse from the meeting of the 

 valves at a large angle, front abruptly raised into a wide semi-elliptical sinus. Entering valve evenly convex; 

 sides tumid, with six or seven strong, rounded, obtuse simple ribs on each side ; mesial ridge broad, pro- 

 minent, very strongly defined from the beak, having three ridges about the size of the lateral ones, each of 

 which dichotoraoses close to the margin. Receiving valve very gibbous, semicircularly arched from the 

 beak to middle of front margin. Mesial sinus deep, strongly defined from the beak, having at first three, 

 subsequently six, small obscurely marked ribs; beak very large, incurved; cardinal area moderately wide." 



Length /i, width 9, depth 6 lines. 



"This species is most nearly allied to S. trigonalis, from which it is distinguished by the more 

 spheroidal form, the obtuse rounding of the sides, and the very small number of its lateral ribs. The 

 distinctly ribbed mesial ridge (fold) separates it from 5. pinguis, as well as its more depressed form, and the 

 fewer and more prominent radiations. Not very uncommon in the carboniferous limestone of Derbyshire." 

 (' British Palaeozoic Fossils,' p. 420.) 



