TEREBRA.TULA. 43 



size ; deltidium in two pieces, surface smooth and punctuated ; margin line nearly straight 

 all round. Loop simple, attached only to crura and extending to near the frontal margin. 

 Length 15, width 8, depth 9 lines. 



Obs. This species is found in the Cornbrash of Northamptonshire, is always accom- 

 panied by T. lagenalis, of which it may perhaps only be a variety j its great width in front 

 and deep longitudinal sinus, as well as the rounded ridges, which in both valves proceed 

 from the frontal edges to the centre of the umbo, seems to M. Bouchard sufficient reasons 

 for separating it from Lagenalis. It is not, however, difficult to find specimens uniting orni- 

 t/tocep/iala to lagenalis, and this last to sublagenalis, but as the typical shapes of each are 

 well distinguishable, it will be found convenient to retain them under distinct specific names. 

 This last-described species is found in the Cornbrash of Northamptonshire, and of 

 Boulogne-sur-mer. 



38. Terebratula Cardium, Lamarck. Plate XII, figs. 13 — 18. 



Terebratula cardium, Lam. 1819. Anim. sans Vert., vol. vi, No. 47. Figured in 



Ency. Method., pi. 141, fig. 6. 



— orbicularis, Sow. 1829. Min. Con., vol. vi, p. 68, tab. 535, fig. 3. 



— furcata, Sow. 1829. Min. Con., vol. vi, p. 67, tab. 535, fig. 2. 



— orbicularis, Morris. 1843. Catalogue. 



— — V. Buck. 1838. Mem. Soc. Geol. de France, vol. iii, l" e 



Serie, p. 160, pi. 16, fig. 3. 



— cardium, Beslongchamps. 1837. Soc. Linn, de Normandie. 



— orbicularis, Bronn. 1849. Index Palseont., p. 1243. 

 _ _ jyOrb. 1849. Prodrome, p. 315. 



— cardium, Dav. 1850. Notes on an Examination of Lamarck's Fossil 



Terebratula. Annals and Mag. of Nat. Hist., June 1850. 



Diagnosis. " T. Testa elongato-ovatd, convexd, plicatd, sulcis longitudinalibus crassis 

 rotundatis : nati prominula." — (Lamarck.) 



Shell inequivalved, more or less oval, elongated, uniformly convex; beak in larger 

 valve straight, truncated by a large entire foramen, separated from the umbo by a narrow 

 concave deltidium in two pieces; lateral ridges, indistinct valves regularly plaited, 

 variable in size, acute, bifurcated when young, and sometimes, though rarely, when adult ; 

 surface punctuated, loop long, attached simply to crura, and extending to near the frontal 

 margin. Length 16, width 12, depth 11 lines. 



Obs. This species was first figured by Bruyere, in the Ency. Meth., and described, in 

 1819, by Lamarck, under the name of Ter. cardium, which name must be preserved. In 

 1829 it was figured and described by Sowerby, under the name of T. orbicularis, and the 

 young under that of T. furcata ; and it is singular to see that most authors (among whom 

 M. D'Orbigny) have made use of Sowerby 's name in preference to Lamarck's, published 

 long before, and figured in the Ency. Meth., to which figure Lamarck refers. The size 

 and number of plaits in this species are very variable ; they are often few in number, wide 



