304 Mr. R. Howse on the Permian System of the 



XXII. — Notes on the Permian System of the Counties of Durham 

 and Northumberland. By Richard Howse, South Shields. 



[Continued from p. 52.] 

 CONCHIFERA. 



17. Pecten PusiLLUs, Schloth. — The author of the 'Perm. 

 Monog.' has, in translating Goldfuss's specific description of this 

 little shell into his 'Monograph' and into English, made a little 

 too free with the Latin original. In the ' Monog.,' " antica 

 valvaj dextrpe majori subplicata" is rendered, "the fore part of 

 the right valve in a great degree subplicate." Now this is both 

 contrary to fact and to Goldfuss's German description as well as 

 to the Latin, and might lead to a little confusion hereafter. 



This Pecten is described as smooth by all authors, and such 

 is its most general appearance; but when the shell is perfect 

 and well preserved, there are to be seen all over its outer surface 

 fine striae of growth running parallel to the lower margin. Also 

 on many specimens numerous fine lines radiate from the um- 

 bones to the same margin. The hinge-line is furnished in some 

 individuals with an area of comparatively great size, but gene- 

 rally it is so small as not to be observable. 



Some specimens of a Pecten which are found in a peculiar yellow 

 conglomerate near Gera in Germany have lately been elevated into 

 a species by Baron Schauroth under the name of Pecten Macrothi. 

 I have examined some fragments of this shell obligingly sent to 

 me by this learned Permian paljeontologist, and I am sorry that 

 I am obliged to consider the distinguishing character which he 

 has pointed out as not of sufficient value to constitute a species. 

 The chief character mentioned as peculiar to this new shell is 

 the distant, very flat lines of growth parallel to the margin. 

 But this is, as above stated, the perfect appearance of the sur- 

 face of Pecten pusillus, to which the Pecten Macrothi, I have no 

 doubt, belongs. 



This species occurs most abundantly in the shell-limestone of 

 Humbleton, and sparingly in all the other localities mentioned 

 in the Table. It is also stated in the ' Perm. Mon.' to occur in 

 the compact limestone at Whitley and Tynemouth. 



17 G. Lima Permiana, King. — Though I had taken single 

 valves of this shell many years ago, yet the slight distinguishing 

 characters it presented have always prevented me from consider- 

 ing it distinct from the preceding. But Mr. Kirkby has, with 

 his usual success, obtained such a fine series of it from the places 

 mentioned in the Table, that its admission into the fauna can be 

 no longer safely resisted. It has also been discovered by Baron 



