[ 373 ] 



XLYI.— ON TEILOBITES AND OTHER FOSSILS, FROM LOWER 

 OR CAMBRO- SILURIAN STRATA, IN THE COUNTY 

 OF CLARE. Br WILLIAM HELLIER BAILY, F.G.S., 

 &c. 



[Read, January 19, 1885.] 



The fossils I bring before your notice were described in the ex- 

 planations to Sheet 133 of the Map of the " Greological Survey of 

 Ireland," illustrating a portion of the county of Clare. 



They were first discovered by Mr. Gr. H. Kinahan and myself, 

 in a small exposure of light-brown shales, in the townland of 

 Ballyvorgal south, on the western extremity of the Slievebernagh 

 Mountains, near Six-mile-bridge. 



These fossils consist principally of trilobites, of the following 

 genera and species : — Dindymene Saidingeri (Barrande), ^glina 

 rediviva, Staurocejjhahis globiceps (Portlook) (probably identical with 

 S. Murchisoni) ; Eemopleurides, sp. perhaps Colbi (Portlock) : Trl- 

 nucleus concentricus, and Agnostus trinodiis, with the brachiopods 

 Orthis calligramnia, var. virgata, and 0. elegantula ; and a pteropod 

 Theca triangularis, all characteristic of Lower or Cambro-Silurian 

 strata of Caradoc Bala age. The first-named of these trilobites, 

 identified by me with Dindymene Haidingeri, is new to Britain, 

 occurring, I believe, in Bohemia. It is figured and described by 

 Barrande in his fine volume on Trilobites, in his " Systeme Silurien 

 du centre de la Boheme," 1st part Palseontologie, vol. 1, as charac- 

 teristic of his fauna seconde, equivalent to Caradoc Bala strata. 



At Belvoir, about half a mile south of Crag-bridge, there is 

 another interesting section, described by Mr. Kinahan, also on the 

 western flank of the Slievebernagh Mountains, where a section of 

 black slates is exposed, Graptolites being the prevailing fossils. 

 Their impressions, double forms of Diplograptus pristis, together 

 with the coiled genus Rastrites ^^eregrimis, are most beautifully 

 impressed upon the shales. 



