Vol. 51.] OP THE MID-COTTESWOLDS. 445 



species common to both regions until the time of the Garantiance 

 hemera, when the faunae become far more similar. These facts seem 

 to show 



(1) That about the time of the opalini hemera there was some 



check to direct communication between the Cotteswolds and 

 Dorset-Somerset. 



(2) That this cbeck was maintained until the time of the Garan- 



tiance hemera, wben a known subsidence, which caused an 

 immense overstep of deposits, allowed of free intercommuni- 

 cation again. 



(3) That, consequently, the Cotteswold region was physically 



isolated, so far as any southward communication was con- 

 cerned, from the opalini hemera until the commencement of 

 the Garantianos hemera. 1 



It will thus be understood why the Cotteswold deposits during 

 certain hemerse yield so many species of bracbiopoda which are 

 entirely peculiar to that region, and why, though the Cotteswolds 

 are much nearer to Dorset-Somerset than the latter is to Normandy, 

 there are far fewer species of brachiopods common to the two 

 English regions than there are common to Dorset-Somerset and 

 Normandy. 



Appendix to Part III. 



It was intended to offer in conjunction with Mr. J. F. "Walker, 

 F.G.S., a paper, as an appendix to the present communication, 

 describing certain new species of brachiopoda, particularly those of 

 the Cotteswolds; but many circumstances have contributed to delay 

 the work. Consequently, I give the following necessary explanatory 

 notes on certain species, hoping that our plans will be fulfilled at 

 some other time. 



1. Notes on certain Brachiopoda. 

 (a) Glossothykis. 



Glossothyris Brebissoni (Deslongchamps). 



1862. Terebratula Brebissoni, E. Desl., Bull. Soc. Linn. Normand. vol. vii. p. 321 

 {teste Deslongchamps). 



1864. Terebratula {JSpithyris) curvifrons, E. Deslongchamps, Brachiopodes, 

 Pal. Franc, pi. xlix. p. 187. 



1884. Terebratula curvifrons, Davidson, ' Monogr. Brit. Fossil Brachiopoda,' 

 vol. v. Pal. Soc. App. to Suppl. pi. xx. fig. 17 only. 



A dorsally (imperforate valve) sulcate, ventrally carinate Terebra- 

 tuloid, the foramen somewhat small, the beak somewhat incurved. 



About 12 years ago I pointed out to Dr. Davidson that the 

 description given by Oppel, as well as the horizon which he assigned 



1 This subject was further treated by the author in ' The Relations of Dundry 

 with the Dorset-Somerset and Cotteswold Areas during part of the Jurassic 

 Period,' Proc. Cotteswold Nat. Field-Club, vol. ix. (1889) p. 374. To accord 

 with present results a little alteration of zonal names is there required. 



