﻿CRETACEOUS BRACHIOPODA. 



39 



being intersected by concentric lines of growth, and which become more numerous and 

 more deeply indented as they approach the margin. Shell -perforations smaller and wider 

 apart than in T. pralonya. Loop short. A large specimen measured 1 inch 11 lines in 

 length, by 1 inch 3 lines in width, and 1 inch 6 lines in depth. 



Obs. Mr. Walker states that this species " may be distinguished from T. pralonya 

 by its surface being covered with fine striae, by its more oval shape, the absence of 

 plications at the front margin, the tendency of the front margin to become inflated, by its 

 shell-structure, by the beak being more incurved, and by the deltidium being shallower. 

 From T. Dallasii it differs by being longer and more oval, and by its striated surface. 

 From T. capillata by being more elongated, by its ventral valve being more tapering 

 towards the beak, by the dorsal valve being less convex, and by its beak being longer." 



A fine series of specimens may be seen in the Woodwardian Museum at Cambridge, 

 and we have figured two of the most remarkable examples that have fallen under our 

 notice. In some specimens the thickening of the margin and front is enormous. 



Position and Locality. It has been found only, as far as I am aware, in the Lower 

 Greensand at Upware, in Cambridgeshire. Not very abundant. 



44. Terebratula abrupta, Tate. Sup., PL II, figs. 17, 17 a, b. 



Terebratula abrupta, Tate. Quarterly Journal Geol. Soc, vol. xxi, p. 41, pi. v, 



fig. 1, 1864. 



Spec. Char. Shell elongated, oval, about one third longer than wide, greatest breadth 

 about the middle, whence it tapers to the beak and front. Dorsal valve most 

 convex at the umbo, plicated near the front. Ventral valve slightly deeper or more 

 convex than the opposite one, with a small rounded rib close to the front ; beak slightly 

 incurved, very short, and truncated by a large foramen. Deltidium and beak-ridges 

 almost inconspicuous ; surface smooth, marked by concentric lines of growth. 

 Length, 2 inches 1 line; width, 1 inch 4 lines; depth, 1 inch. 



Obs. This fine Terebratula has been well described and figured by Mr. Ralph Tate. 

 It appears to be tolerably distinguishable from T. obesa, T. biplicala, and T. pralonya, by 

 its very short and transversely truncated beak. In some examples the extremity of the 

 beak is much worn, from the shortness of the pedicle. I have not seen the loop ; but it 

 was, in all probability, short and simple, and not unlike that of T. bijplicata. 



Position and Locality. Mr. Tate found this species in the White Limestone or Upper 

 Chalk of Lisburn, near Antrim, and at Moira, in Ireland, and where it is rare. Specimens 

 in the Portlock Collection in the Museum of Practical Geology are from Dungiven, 

 County Kerry, Ireland. Mr. S. A. Stewart obtained it likewise at Colin Glen, near 

 Belfast. 



