CAMAROPHORIA. 23 



exist also a slight difference in the shape of the intermediate process which unites the 

 spiral coils ; and until this point has been clearly ascertained, it will, I think, be preferable 

 to consider both separate, although closely allied, species. There also appears to exist 

 some difference in the external spines. 1 



Loc. A. pectinifera appears to be a rather uncommon shell in the limited number of 

 localities where it has been hitherto discovered. In England it has been found from the 

 shell limestone of Tunstall, Humbleton, and Hylton, and in the magnesian conglomerate 

 of Tynemouth, and by Messrs. Howse, Kirkby, and Professor King. In the German 

 'Zeichstein' it is described from Milbite, Corbusen, and Gera. Also from Kirilof, 

 Tioplova, and Bielebei, in Russia. 



i^7y— RHYNCHONELLID^E. 2 

 Genus — Camarophoria, King, 1846. 8 Plate II. 

 {Vide General Introduction, Vol. I, p. 96, 1353.) 



The external and internal characters of this excellent genus have been fully described 

 by Professor King, and again detailed in the General Introduction to the present work, 

 so that there remains but little further to be added to what has been already published. 



The excellent material in the possession of Messrs. Howse and Kirkby has, however, 



1 M. De Verneuil observes tbat " T. pectinifera differs from T. Roissyi but by the absence of a sinus 

 in either valve, and by the horizontality of its margin, comprised in a same plane. It is probable enough 

 that it is but a variety, and that specimens will be found which will connect the two species together ; but 

 it would deserve not the less to be considered as a remarkable variety, by its preponderance more at one 

 epoch than at another ; for in Russia, as in England, T. pectinifera is peculiar to the Permian system, 

 and if it exists in the Carboniferous system of Belgium, it is at least exceedingly rare." 



Terebratula Royssiana, Keyserling, 1846 (' Reise i d. Samojedenland ' of Dr. Schrenk, vol. ii, 

 p. 109, pi. iv, figs. 31 — 33), belongs to the genus Athyris, and is specifically different from A. Royssii, Lev., 

 as well as A. pectinifera. 



2 The occurrence of the genus Rhynchonella in the Permian period was noted by D'Orbigny at p. 167 

 of the first volume of his 'Prodrome de Paleontologie Stratigraphique ' (1849), as typified by Terebra- 

 tula Geinitziana, De Verneuil, a shell found by the authors of the ' Geology of Russia,' at Schedrova, near 

 the mouth of the Vaga (Dvina), as well as by Count Keyserling in the uninhabited forests near the river 

 Oukhta (province of Archangel), Russia. 



From not being acquainted with this shell, and having overlooked its mention as a Rhynchonella, I 

 queried the existence of the genus in the Permian period when publishing the Tables contained in the 

 English, French, and German editions of my General Introduction. It must, however, be observed, that 



3 'Annals and Mag. of Nat. History,' vol. xviii, August, 1846. 



