254 NOTES ON THE PERMIAN SYSTEM OF 



adpressed spines of the lower valve, and the strong radiating 

 strife which are generally present on both valves. In old indi- 

 viduals the front margin strikes off nearly horizontally, and 

 forms a kind of syphonal tube in front. There is also a ten- 

 dency in this species to form a new internal surface behind the 

 old upj)er valve, for the purpose of contracting the interior of 

 the shell. It is not an additional, third valve, as King has ab- 

 surdly supposed, for it is essentially connected with the upper 

 valve, and must have been formed by the upper lobe of the 

 mantle. 



Most plentiful in the shell-limestone of Humbleton, Tunstall, 

 and Dalton. In the compact-limestone it is very rare. 



G. STREPTORHYNCHUS, King. 



1. S. PELARGONATUS, ScJllotJl. 



This neat species is not included in the list of Permian fossils 

 of the " Geol. Russ." as a British species ; and, indeed, when I 

 became acquainted with some of our palaeontologists, I found 

 them entirely unacquainted with it. This was remarkably the 

 case with Mr. King, who had not the slightest knowledge of the 

 shell when I first showed it to him, and to whom I presented a 

 fine series of Dalton specimens afterwards, that he might be able 

 to illustrate the species in his " Monograph." 



The general form of this species is now, through the figures 

 of Geinitz and King, joretty well known, and the interiors have 

 lately been very accurately represented by Mr. Davidson, in his 

 work on the Permian Brachiopoda, pi. ii. figs. 32-42. 



Though a rare species generally, numerous examples are occa- 

 sionally found in a very limited space. It is the common asso- 

 ciate of P. latirostratuSy both at Dalton-le-dale and Tunstall, 

 where numerous examples have been taken by Mr. Kirkby and 

 myself. 



7. CAMAROPHOPvIA, Xinff. 



1. C. SCHLOTHEIMI, V. Buch. 



It is very probable that the specimens figured by Yerneuil in 

 '' Geol. Euss." under a distinct name, Terehratula sitperstes, be- 

 long to the present species; but as 1 have not seen any of the 



