40 BRITISH CRETACEOUS BRACHIOPODA. 



Obs. Nearly all our Cretaceous Terebratulse had a short loop. T. longa, of Rcemer, 

 is an exception, in it the apophysary system extended to near the frontal margin, as in 

 Ter. lagenalis, &c. 



lG. Terebratula capillata, D'Archiac. Plate V, fig. 12 



abed 



Tekebkatula capillata, D'Archiac, 1846. Bull, de la Soc. Ge'ologique de France, 



vol. iii, 2de ser., p. 336 ; and 1847, Memoires de la Soc. 

 Geol. de France, vol. ii, 2de ser., p. 323; pi. xx, figs. 1, 

 2, and 3. 

 — — Bronn. Index Pal., p. 1232, 1848. 



Diagnosis. Shell irregularly oval, or somewhat pentangular, longer than wide; valves 

 unequally convex, the dental or larger one the most so, no mesial fold or sinus ; valves 

 regularly convex to the front; margin line presenting a slightly elevated curve, or 

 biplication in front ; beak short, rounded and recurved, diagonally truncated by a large 

 circular foramen, a portion of which is completed by a small deltidium in two pieces; 

 beak ridges not always well defined, soon turning in to meet the hinge margin ; surface 

 ornamented by a vast number of minute radiating capilliform elevated striae close together, 

 unequal, and more or less undulating, these being intersected at variable distances by 

 concentric lines of growth. Structure punctuated, interior unknown, but probably 

 possessing a short loop. Length 13, width 11, depth 8 lines. 



Obs. Among the different specimens sent for my inspection by Messrs. Eitch and 

 Carter, from the Red Chalk of Hunstanton Cliff, Norfolk, I was agreeably surprised to find 

 two perfectly characterised specimens of the Terebratula capillata, D'Archiac, one of the 

 most characteristic fossils of the Tourtia of Belgium, the small narrow capilliform waving 

 striae being perfectly preserved on our specimens, and distinguishes them from the other 

 species peculiar to the Cretaceous period. I am surprised to find, in p. 172 of M. D'Orbigny's 

 'Prodrome,' that author does not perceive the marked differences between this and Ter. 

 depressa of Lamarck, to which last he refers the present form, stating these differences to 

 be only due to age and superficial wearing ; this is, however, far from being the case ; the 

 very shape in both is quite distinct; the elongated beak and deltidium of T. depressa 

 alone would distinguish it from T. capillata; and from an extensive and well-preserved 

 series of both forms collected by myself in Belgium, I feel no doubt that at all ages 

 T. depressa was smooth, while T. capillata is ornamented as described above. T. capillata 

 has been well described, and beautifully illustrated, by Viscount D'Archiac, and is not very 

 rare at Tournay, in Belgium. 



Plate V, fig. 12 a6c . Specimen from the Red Chalk of Hunstanton Cliff, Norfolk, in 



the collection of Mr. Fitch, of Norwich. A similar one is 

 preserved in the collection of Mr. Carter, of Cambridge. 

 ,, figs. 12" and 12. Enlarged illustrations. 



