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SUPPLEMENT TO THE BRITISH 



Length 8, width 6, depth 4 lines. 

 Obs. — This small species rarely exceeds the dimensions above given, and it is usually 

 smaller. It is remarkable on account of its small raised wave in front, and its almond 

 shape. It occurs, according to Mr. Walker, in great numbers in the Lower Calcareous 

 Grit. It is often found in masses, specimens of which may be seen in the York Museum. 

 It has been named by Mr. J. F. Walker after W. H. Hudleston, Esq., F.G.S., who has 

 done good work among the Oolitic Rocks of Yorkshire. 



99. Terebratula sphceroidalis, Sow. Dav., Ool. Mon., p. 56 ; PI. IX, figs. 9 — 18 (not 



19), and Appendix to vol. i, PI. A, fig. 16. 



I believe I was in error in stating (at page 56 of my Oolitic Monograph) that Ter. 

 sphceroidalis and T. bullata belonged to one species. Mr. E. Deslongchamps, in vol. ii of 

 the ' Bulletin de la Societe Linneenne de Normandie,' p. 44, pi. iv, figs. 11 — 13, 1857, 

 refers some forms to T. sphceroidalis to which he subsequently in his " Brachiopodes 

 Jurassiques" gave the name of T. conglobata. I consider he was right in so doing, as they 

 differ sufficiently from Sowerby's T. sphceroidalis to be separated from that shell. I 

 think, however, he was mistaken when he followed me in placing T. bullata as a synonym 

 of the species under description. The biplication observable in T. bullata is quite 

 sufficient to distinguish it from T. sphceroidalis. I am supported in this view by Mr. 

 J. F. Walker, who has made a special study of these species. T. sphceroidalis always 

 presents a more or less globular or globose shape, like a marble or billiard-ball. 

 Sometimes after an interruption in growth (on resuming which it becomes suddenly 

 inflated) a wide ring is formed round its margin. 



A foreign example in the British Museum, of which I gave a figure in the ' Annals 

 and Mag. of Nat. Hist.,' 2nd ser., vol. 9, pi. xiv, measures 24 lines in length by 23 in 

 width, 21 in depth. Mr. E. Deslongchamps figures equally large specimens from the 

 neighbourhood of Niort (Deux Sevres), but none of our British examples have attained 

 quite as large proportions. 



It occurs in the Inferior Oolite, but according to Mr. E. Deslongchamps in the beds 

 characterised by Am. opalinus and Am. Murchisoni. It appears in the beds containing 

 Am. Sauzei, but is especially abundant in the Zone of Am. Iiumphresianus, and attains 

 its largest size in that of Am. Parkinsoni. 



