146 Scientific Proceedings, Royal Dublin Society. 
range from the base of the formation upwards; as in all the lowest 
rocks fossils of Upper Llandovery and Caradoc types occur. I 
may also suggest that in Munster there cannot be a great thick- 
ness of strata absent between the Silurians and the Cambro- 
Silurians ; because at Ballycar in the Cratloe Hills there are in 
the latter the above mentioned colony of Upper Llandovery 
(Silurian type) fossils. 
I have not examined to any great extent the rocks of these two 
formations in Ulster, and therefore cannot add anything from 
my own knowledge to what has been ascertained of them by 
others. 
