Vol.59-] A LOWER-GREBNSAND FOSSILIFEROTTS BAND. 2-19 



are being even more acutely felt by stratigraphists in this and other 

 countries in the separation of the Permian and Carboniferous 

 systems on the one hand, and of the Trias and Permian on the 

 other. And we must be prepared either to find place for ambiguous 

 developments of the kind discussed in this paper within the 

 boundaries of our established systems ; or to create a series of 

 ' buffer-states.' under the designation of ' passage-beds,' to protect 

 our systems from ever coming into contact, where the succession 

 is complete and where there may be neither stratigraphical nor 

 biological break. 



In concluding this part of our paper we wish to render thanks 

 to Mr. E. T. Newton, P.R.S., F.G.S., for his great assistance in 

 determining the echinodermata and other fossils, and for first 

 pointing out to us the Upper Cretaceous affinities and anomalous 

 characters of the fauna. We are also indebted to Mr. H. Woods, 

 M.A., F.G.S., for the care which he has so willingly bestowed on 

 the determination of the lamellibranchs. 



Part II. — Description of the Brachiopoda. 

 [Plates XVI-XVIII.] 

 Terebratula capillata, d'Archiac. (PI. XVI, figs. 1 a-6.) 



1842. Spondylus undulatus, Geinitz, ' Char. d. Sachs.-Bohm. Kreidegeb.' pt. iii, 



p. 82. 

 1847. Terebratula capillata, d'Archiac, ' Fossiles du Tourtia ' Mem. Soc. Geol. 



France, ser. 2, vol. ii, p. 323 & pi. xx, figs. 1-3. 

 1852. Terebratula, capillata, Davidson, ' Brit. Cret. Brachiop.' Monogr. Pal. Soc. 



p. 46 &■ pi. v, fig. 12. 

 1868. Terebratula capillata, Schloenbach, in Beneeke's Geogn.-Palaont. Beitrage, 



vol. i, p. 454. 



1871. Terebratula capillata, Quenstedt, ' Brachiopoden ' [ Petrefactenkunde 



Deutschlands, pt. i, vol. ii.] p. 385 & pi. xlviii, figs. 75-76. 



1872. Terebratula capillata, Stoliczka, Pal. Indica, 'Cret. Fauna S. India' vol. iv, 



p. 23 & pi. vii, fig. 1. 

 1872. Terebratula capillata, Geinitz, ' Elbthalgebirge ' p. 154 & pi. xxxiv, fig. 12. 

 1874. Terebratula capillata, Davidson, 'Brit. Cret. Brach.' Suppl. Monogr. Pal. 



Soc. p. 33 & pi. vii, tig. 2. 

 1878. Terebratula capillata, Deicke, ' Die Brachiop. der Tourtia von Mulheim ' 



p. 16 & (pi.) figs, la-lb. 



Of this characteristic species we have collected at Shenley a large 

 number of specimens in all stages of growth, and many remarkable 

 abnormal forms. The test is beautifully preserved, showing the 

 small, narrow, capilliform, waving striae intersected by concentric 

 lines of growth. This species seems to be very variable in the con- 

 vexity of the valves, in the relative length and width of the shell, 

 and in the presence or absence of a wide fold at the front margin : all 

 these varieties occur in the Tourtia of Belgium, as shown in a fine 

 series sent by M. Piret, of Tournay. The globose specimens appear 

 to be very similar to those found in the Red Chalk of Hunstanton 

 (Norfolk), and at North Grimston (Yorkshire). Some of the speci- 

 mens of T. capillata from Shenley so closely resemble those from 

 Tournay in colour and in the composition of the matrix, that it 

 would be impossible to separate them if they got mixed. D'Archiac 



Q..J.G. S. No. 234. s 



