110 
rently by no means improbable that Mr. Gumming, and 
others, may not have been mistaken in supposing some of 
the lower beds to be of Cambrian age. 
I am indebted to Mr. H. H. Bailey, F.G.S., Acting Palseon- 
tologist to the Irish Geological Survey, for his kindness in 
drawing the specimens. 
EXPLANATION OF PLAfES. 
Plate I. 
Fig. 1. — Specimen of Nemevites ? Monensis, from Oakhill, 
in Braddan ; natural size. 
Fig. 2 . — Linguella Davisli ? (Mc.Coy), from the same 
locality; natural size. 
Plate II. 
Fig. 1. — Specimen of Nereites'^. Monensis, from the slate - 
quarry of Mary Yeg, in San ton; natural size. 
Fig. 2. — Oval valves of a bivalve shell ? from the same 
locality; natural size. 
