46 BRITISH OOLITIC AND LI ASIC BRACHIOPODA. 



42. Terebratula subpunctata, Dav. Plate VI, figs. 7 — 10, 12, 16? 



Diagnosis. Shell inequivalved, ovular ; valves almost equally convex ; beak rounded, 

 recurved, and truncated by a rather large entire foramen of an elongated shape, projecting 

 over the umbo, so as to conceal the triangular deltidium, in two pieces, existing under it, and 

 therefore rarely visible. The ridges of beak soon become indistinct ; marginal line slightly 

 curved and raised in front ; surface smooth, punctuated ; loop attached only to crura, and 

 extending to about a little more than one third of the length of shell ; the lamella is 

 strong and wide. Length 28, width 20, depth 17 lines. These are the dimensions of 

 the largest specimen known, but the average size is much less. 



Obs. The different figures I have given in Plate VI will show, to a certain degree, 

 the extent of variability observed in this shell, which is much deeper, stronger, and more 

 convex than in true T. punctata ; it is, however, allied to that species, and many specimens 

 pass from one type into the other. The beak is less recurved, and deltidium more apparent, 

 in T. punctata, its front being also more rounded. In many specimens of this species we 

 observe a well-defined flatness at the umbo ; it cannot be considered a character, but rather 

 a deformity, caused by pressure in the young state, retarding the normal and regular deve- 

 lopment of the shell, which is also shown by strong lines of growth. Fig. 8, and still 

 more fig. 12, illustrate how much such a malformation changes the general aspect of the 

 shell. Ter. subpunctata, which I have so named from its close affinity to punctata, is 

 abundantly distributed in the marlstone or middle Lias of South Petherton, near Ilminster, 

 and in other localities. On the Continent it was found by M. Deslongchamps and myself, 

 in the Liasic beds of Evrecy, &c. Along with the specimens found at South Petherton, by 

 Mr. Moore, was one (fig. 16) which I have been unable to place anywhere, except under the 

 head of a deformity of the shell under consideration, the form of its beak and foramen 

 being the same, and it has many visible marks of pressure upon it. Figs. 8, 10, 12, are 

 from the Collection of Mr. Moore. 



43. Terebratula indentata, Sow. Plate V, figs. 25, 26. 



Terebratula indentata, Sow. Min. Con., 1825, vol. v, p. 65, tab. 445. 



— — Morris. Catalogue, 1843. 



— — Bronn. Index Palaeont., 1849. 



Diagnosis. Shell elleptical, longer than broad ; valves nearly equally convex ; beak 

 recurved, and truncated by an entire foramen; lateral ridges lost at a short distance 

 from the foramen, sometimes notched in front ; surface smooth, punctuated ; loop short, 

 simply attached to the crura. Dimensions variable; size of largest specimen, as yet 

 observed,— length 14, width 10, depth 9 lines. 



