146 



PKOCEEDLNGS OF THE GEOLOGICAL SOCIETY. [Dec. 17, 



the Brandschiefer of Oschatz is unmistakeable, and if the carbonaceous 

 shales of Autun and the Murgthal should prove to be really Permian,' 

 as some suppose. 



E. exigua is accompanied by a feebly developed Beyrichia (B. 

 PyrrJice), to which the remarks made above on B. subarcuata equally 

 apply. 



5. Estheria Portlockii, Jones. — A unique specimen, and that a cast, 

 in an isolated deposit, is the basis for the determination of this species. 

 Yet it bears such evident proofs, in shape, surface, and relative size, 

 of its Estherian relationship, that I do not hesitate to dedicate it to 

 the eminent geologist who first noticed it (under the name of " Posi- 

 donia minuta ") as occurring at Ehone Hill, near Dungannon, Tyrone, 

 where he found it in the shale-seams between beds of the red sand- 

 stone containing Palceoniscus catopterus. 



The Geological Survey will ultimately clear up all doubt as to the 

 geological place of this sandstone ; in the meantime I follow Sir P. 

 Egerton and Professor Morris in alluding to it as of Permian age ; 

 and its position on the map does not seem inimical to this view. 



Palceoniscus may or may not have had both marine and freshwater 

 species, like many recent genera of fishes ; and therefore no collateral 

 evidence at present exists as to the habitat of E. Portlockii. 



6. Estheria minuta, Alberti, sp. — This little Cyclas-like Crustacean 

 has long been a type-fossil for the Keuper, and more especially for 

 the lignitic deposits (Lettenkohle) at the base of the Keuper, which 

 have been sometimes grouped as Lower Keuper and sometimes as 

 Upper Muschelkalk. E. minuta occurs in the Lower Bunter of 

 Eastern Erance (Soultz-les-bains, Bas Ehin); in the Upper Bunter 

 at Gersfeld in the West Rhon (Hassencamp), and near Dassel in 

 Hanover (Volger) ; in the Muschelkalkf at Durlach in Baden (Sand- 

 berger), and at Weimar in Thuringia (Seebach) ; in the Lettenkohle 

 of Haute Saone and Bas Bhin, Baden, Wiirtemberg, Bavaria J, Ha- 

 nover, and Thuringia ; in the Lower Keuper at Hall in Swabia (Yon 

 Dechen) ; in the Upper Keuper of Tubingen in Wiirtemberg (Bronn). 



Table of the Distribution of Estheria minuta in the European Trias. 



Members of the 

 Trias. 



England. 



Eastern 

 France. 



Baden, Wiir- 

 temberg, and 

 Bavaria. 



Hanover. 



Thurin- 

 gia. 





fe 



* 



* 



* 



*? 

 *? 



* 



*? 



Muschelkalk 





f The "Lower Keuper" and the " Muschelkalk" in this list may both really 

 have reference to the Lettenkohle group. 



\ In his ' Geognostische Beschreibung des bayerischen Alpengebirges,' &c, 

 1861, Gumbel states that "Posidonomya minuta " {Estheria minuta) occurs in 

 each of the three divisions of the " Lettenkohlengruppe," the lowest division of the 

 Keuper in the Bavarian Alps, — the " Hauptdoloniit-Gruppe " being the middle, 



