18 BRITISH CARBONIFEROUS BRACHIOPODA. 



Palaeozoic Fossils' (p. 410), Professor M'Coy assimilates botli Sowerby's and Phillips's 

 representations of T. juvenis with the Carboniferous shell, but I have not been so 

 fortunate as to meet with any agreeing with the adult condition described by Professor 

 Phillips ; and the Carboniferous specimens so named in the Cambridge Museum (Plate I, 

 fig. 17) do not certainly represent the Devonian species. This species seems to be easily 

 distinguished from well-authenticated young of T. hastata by its more depressed appear- 

 ance, as well as by the shape and curve of its frontal margin. We have named it after 

 the locality where it abounds, and it will be as well also to notice that all the 

 examples had a reddish tinge, which may perhaps be due to remains of colour. 



Loc. It abounds at Gilling, in Yorkshire. Dr. Fleming has the species from West- 

 lothian, Scotland (Plate III, fig. 1). 



Terebratula (?) subtilita, J. Hall. Plate I, figs. 21, 22. 



Terebratula subtilita, J. Hall. In Howard Stransbury's work, ' Explanation of tbe 



Valley of the Great Salt Lake of Utaty,' p. 409, pi. ii, 

 figs. 1 a, b, and 2 a, b, c, Philadelphia, 1852. 



Spec. Char. Ovate, longer than wide, and somewhat tapering at the beaks ; valves 

 almost equally deep or convex, but most inflated at and about the umbone of the dorsal 

 one ; the mesial fold forms a moderately elevated curve, whence the lateral portions of 

 the valves rapidly decline. In the ventral valve, a shallow sinus commences at about 

 half the length of the valve, and extends to the front, which there presents an elevated 

 convex curve, indenting to a lesser or greater degree that of the opposite valve. Beak 

 moderate in dimensions, and but little incurved ; the ridges are obscurely defined ; 

 foramen circular, and in general contiguous to the umbone of the opposite valve. 

 External surface smooth, marked only by a few lines of growth ; interior unknown. 



Length 12, width 10, depth 7 lines. 

 8, „ 7, „ 5 lines. 

 Obs. Of this species I have hitherto been able to examine but two British individuals, 

 obtained by Professor Phillips, in a yellow Carboniferous grit at Mayen Wais, and 

 which appear to be identical with T. subtilita of Hall, an opinion first expressed by 

 Professor De Koninck, from the inspection of my figures, before I possessed the means 

 of direct comparison. T. subtilita appears to abound in the Carboniferous limestone near 

 the village of Pecos, in the Rocky Mountains of New Mexico, where it is associated with 

 Prod, semireticulatus and Spirifera striata. It also occurs in the same beds at 

 Sierra Madre and Sierra de Mogoyon, and M. Marcou possesses specimens from the 

 mouth of the Rio San Pedro, in the Rio Gila (Sonora). Professor Hall mentions it 

 from the Missouri. 



I am, however, very uncertain whether this shell belongs to the genus Terebratula, as 



