120 PERMIAN FOSSILS. 



appears only to differ from the former in being narrower and more acuminated behind. 

 Occasionally, however, a variety of the present species occurs, which can scarcely be 

 distinguished from C. crumena: in short, both species apparently merge into each other 

 so completely, that many would be inclined to consider them as specifically inseparable. 

 The Lamarckian might very reasonably instance them as proving proximate species to 

 be modifications of each other; while, at the same time, his opponent might with 

 equal reason contend for their being the result of a single specific creation. There is 

 another species, undescribed, occurring in the Carboniferous Limestone of Weardale, 

 Durham, and having a still closer resemblance to C. ScJdotheimi in form ; but its spatula- 

 shaped process is decidedly more curved, — so much so, that its termination is not far 

 removed from the anterior end of the arch of the large valve. 



This species is a very common fossil at Tunstall Hill and Humbleton Quarry, and a 

 less common one at Ryhope Field-House Farm, in the Shell-limestone. I procured a few 

 specimens in the Breccia at Tynemouth Castle Cliff. Schlotheim first noticed it as 

 occurring in the bituminous Marl-slate (Kupferschiefer) of Schmerbach. Geinitz and 

 others record its occurrence in the Zechstein of Corbusen, Schwaara, Ropsen, Milbitz, 

 Ilmenau, Sangerhausen, -Schmalkalden, Schmerbach, and Kamsdorf M. de Vemeuil 

 notices it as occurring in the Carboniferous Limestone of Mount Cheractau near 

 Sterlitamak, at Sarana on the Ufa, and at Cosatchi Datche, in Russia.^ 



Camarophoria globulina, Phillips. Plate VII, figs. 22, 23, 24, 25. 



Terebratula globulina, Phillips. Encyc. Met. Geology, vol. iv, pi. iii, fig. 3, 1834. 

 Camarophoria — „ King, Annals of Nat. Hist., vol. xvii^, p. 28, 1846. 



— — ,, King, Catalogue, p. 7, 1848. 



Terebratula corymbosa, Howse. Trans. T. N. F. C, vol. i, p. 253, 1848. 



Diagnosis. — Sub-globular ; rarely exceeding a quarter of an inch in diameter ; 

 smooth ; slightly sinuated in front. Sides (looking down on the perforate valve) higher 

 than the front, which falls considerably below the latter : sides and front more or less 

 ribbed. Bihs sharp and simple. TJmhones slightly projecting and incurving. Both 

 valves convex. 



This small species, first named and figured, though not described, by Professor 

 Phillips, is with difficulty distinguished from young specimens of Camarophoria 

 ScMotheimi : it may be known, however, by having both valves of nearly the same 

 convexity ; but the difference may be also recognised by comparing it with full-grown 

 specimens of the latter, which it will be seen could not have had the ribs so prominent 

 when young as they are in correspondingly sized specimens of C. globulina. 



^ Perhaps the shell discovered by M. de Vemeuil in the Russian carboniferous limestone, and identified 

 with the Camarophoria ScMotheimi, may be the same as the species occurring in the carboniferous limestone 

 of Weardale ; and the C. superstes, the C. crumena, — both having a similar marginal outline. 



