316 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 9, 



Mytilus gregarius, Goldf. Pecten paradoxus, Miinst. 



*Gervillia Hartmanni, Miinst, * comatus, Miinst. 



tortuosa, Phil. Hinnites, sp. 



lata, Phil. Gryphaea gigantea, Sow. 



* Pecten demissus, Phil, sandalina, Miinst. 



* cingulatus, Goldf. 



I have marked with an asterisk all the species of the mariy sand- 

 stone and the hydroxide oolite which have been found by me in the 

 Cephalopoda-bed. 



The equivalent of this bed occurs in the Province of Luxembourg, 

 and is well described by Drs. Chapuis and Dewalque * as Lias supe- 

 rieur, 6me etage, — Schiste et Maime de Grand Cour ; and is re- 

 garded by M. Dumont as forming the superior part of the Lias. 

 The schist is worked for the extraction of bitumen at Aubange, 

 where numerous fossils have been found. 



This bed is la terre afoulon of Boblaye, — la marne superieure of 

 Sauvage and Buvignier. It corresponds to the Lias ^ and to the 

 Brown Jura a of Quenstedt ; to the Posidonien-schiefer of Roemer ; 

 and to the Upper Lias Shale of Phillips. I regard it as consti- 

 tuting the upper stage of the *' superior Lias." The authors found 

 the following Ammonites and Belemnites in this bed : — 



* Ammonites communis. Sow. *Ammonites variabilis, d'Orb. 

 * concavus. Sow. Belemnites acuarius, Schl, 



* heterophyllus. Sow. compressus, Voltz. 



* radians. Rein. * tripartitus, Schl. (elongatus, 



* Raquinianus, d'Orb. Miller). 



serpentinus, Schl. 



Our Cephalopoda-bed and sands are equivalent to Professor Quen- 

 stedt' s graue Kalkstein-Bank mit Ammonites Jurensis, forming the 

 bed t,, the uppermost of his schwarzer Jura f (Lias), together with 

 the schwarze Thon mit Ammonites opalinus J, forming bed a of his 

 brauner Jura, 



Through the kindness of Dr. Fraas, of Stuttgart, I have before 

 me a series of authentic specimens of Ammonites from these German 

 beds, which I have compared with the Ammonites from the bed at 

 Frocester Hill ; and there cannot be a doubt as to the identity of 

 the species : the specimens before me are — 



Ammonites Jurensis, Ziet. Lias ^, Balingen, Boll. 



insignis, Schl. Lias (, Balingen. 



radians, Schl. Lias ^, Aalen. 



torulosus, Ziet. Brown Jura a, Laufen. 



opalinus, Quenst., Rein. Brown Jura a, Laufen and Gmiind. 



The Frocester Ammonite-bed is therefore undoubtedly the equi- 



* Description des Fossiles des Terrains Secondaires de la Province de Luxem- 

 bourg. 



t See Fraas on tlie Jura Formation, Quart. Journ. Geol. Soc. vol. vii. Part 2. 

 Miscell. p. 54 et seq. 



X *' Sehr machtig im untersten Gliede findet sich Ammonites torulosus." — 

 Handbuch der Petrefacten-Kunde, p. 11. 



