168 William Hellier Baily 



Two other fossil localities, also in Silurian strata, have 

 been observed more inland, one of them being a little south of 

 Stamullin, close to the river Delvin, where a Crinoid head, doubt- 

 fully referred to Glyptocrinus, and single-celled Graptolites — 

 probably G. Hisingeri — were long since obtained by the Geo- 

 logical Survey Collectors, from grey shales and grits. The other 

 is situated about a mile and a-half west of Balbriggan, at an old 

 quarry on the road to Balscaddan, where similar grey shales 

 yielded a few fossils, amongst them Orihis calligramma and 

 Tkeca triangularis. * 



Lower Silurian fossils ; near Balbriggan, Co. Dublin. 

 Hydrozoa : Graptolites. 

 **Diplograpsus pristis. 

 ***Graptolithus Hisingeri. 

 „ tenuis. 



Actinozoa : Corals. 

 **Favosites fibrosus. 



Mollusoa : Brachiopoda. 

 Crania ] 



**Lept8ena sericea, 

 Orthis Actonise. 



* „ calligramma. 



* „ porcata. 

 *Strophomena alternata. 



* ,, deltoidea. 



Theca triangularis. 



Ptfropoda. 

 Eciiixodermata. 



Crinoid fragments. 

 Glyptocrinus 1 



Crustacea : Phyllopoda. 

 Beyricliia, species undetermined. 



Trilobita. 

 Calymene brevicapitata. 

 Cybele verrucosa. 



Carboniferous Limestone is the prevailing formation in the 

 immediate neighbourhood of Dublin, and although for the most 

 part covered by drift, is observable at the numerous quarries 

 opened for economical purposes, at coast sections, and Railway 

 cuttings. 



Sections of this formation are to be seen on the south of 



* Explanation of Sheets 91 and 92, Geological Survey of Ireland, p. 21. 



