C, Spence Bate — On Archceastacus in the Lias. 307 



Clevelastd Shale .... Ctenacanthusformosus,'Ne^''b. 



,, furcicarinatus, Newb. 



Cladodus Patersoni, Newb. 



Orodus variabilis, Newb. 



Folyrhizodus modestus, Newb. 



Falmoniscus, 2 sp. 

 Erie Shale .... Leior'hi/nchns mesocostale, Hall. 



Spirifera disjuncta, Sby. 



In regard to tlie fish quoted above from the Cleveland shale, Dr 

 Newberry remarks (Pal. of Ohio, vol. ii. p. 94) : — 



"■ To the palaeontologist it is scarcely necessary to say tliat such 

 a group of fossils as that enumerated above could only come from 

 Carboniferous rocks, most of the genera here represented being 

 exclusively confined to that formation. The only exception is 

 Ctenacanthus, of which one or two doubtful species have been 

 described from the Devonian rocks of the Old World, and we have 

 obtained one well-marked and beautiful species from the Huron 

 shale (Portage) (Ct. vetustus, Newb.)." 



Writing of the fossils of the Berea Grit, the same author savs 

 (p. 90) :- _ 



" The most interesting fossil found in this formation is a plant 

 that covers some of the surfaces of the layers at Bedford, and which 

 I have been unable to distinguish from Annularia longifolia of the 

 Coal-measures." 



In regard to the Brachiopods in the list given above, Ortliis 

 Michelini was described from the Lower Carboniferous rocks of 

 France ; Streptorhynchus crenistriatum from those of Yorkshire ; 

 Chonetes Logani from the Burlington group of Iowa ; Bhynchonella 

 Sagerana from the Marshall Group of Michigan, and of Spiriferina 

 solidirostris and Syringothyris typus Dr. Newberry writes (p. 92) : — 

 " They are characteristic of the Lower Carboniferous rocks of other 

 States." 



The evidence of the age of the Cuyahoga Shale, and therefore of 

 the Trilobite above described, could scarcely be more complete. 



IV. — Arcsjeastacus {Erton) Willemcesii, a New Genus and 



Species of Eryonid^} 



By C. Spence Bate, F.E.S. 



(PLATE X.)3 



THE several species of Eryon, described by various authors, appear 

 to be distinguishable as separate genera, which are as definable 

 from one another as from the recent forms of Polycheles and 

 Willemoesia ; but the variability appears not to be greater than in 

 those that are separated in time through geological aeons, than in 

 those that are contemporaneous in geographical space. 



^ Bead before Sectioa C, British Association, at Soutbport, 1883. 



^ Mr. Spence Bate bad most obligingly sent up to the Editor a pencil dra'wiug, 

 being a restoration of Mr. Lee's fossil, for the Artist to copy; but as Mr. Lee sub- 

 sequently kindly allowed the original specimen to be drawn, it was deemed advisable 

 to reproduce the actual fossil without additions from recent specimens. — Edit. 



