Batly— Cambrian Rocks and Fossils. 393 
remains. These additions to the Cambrian fauna he described in 
papers read before the Geological Society of Dublin, and published 
in their Proceedings.* 
That much-lamented gentleman, in his frequent search amongst 
these hard and apparently unyielding grits, obtained better specimens 
of the Oldhamia than those examined by the late Professor Forbes ; 
so that he was enabled to write an elaborate treatise, with descriptions 
of the different forms assumed by the genus, illustrated by excellent 
woodcuts, which was published in the Transactions of the Royal 
Irish Academy.f In that treatise, presuming that Professor Forbes’s 
leaning was towards their alliance with the Polyzoan Molluscoids, 
he professes to dissent from that view of their relations, expressing 
his opinion ‘ that they were more probably the polypidoms of extinct 
Hydrozoa, than cenicia of Polyzoa’ (p. 561). It will be seen, how- 
ever, that he only reiterates the opinion of Professor Forbes, as the 
descriptive card, in Professor Forbes’s own handwriting, which was 
attached to the specimens in the Geological Survey Collection 
(Museum of Irish Industry), of which the following is an exact copy, 
will testify :—‘ Oldhamia (Forbes). The most ancient fossils yet 
discovered : believed to be the remains of marine animals belonging 
either to Hydrozoa (Corals) or Polyzoa (Compound Mollusca).’ 
In his paper, Dr. Kinahan supplies scientific descriptions of the 
Species named Oldhamia antiqua and O. radiata by Professor Forbes, 
and, in addition, describes what he considers to be a third species, 
under the name of O. disereta, from Carrick Mountain, a locality 
from which some of the most distinct specimens of O. antigua were 
obtained, of which species I believe this to be merely a variety. 
There remain, then, only the two well-marked species, originally 
named by Professor Forbes Oldhamia antiqua and O. radiata. The 
first of these, O. antiqua, is most frequent in the shales, and occurs 
as clearly defined impressions in beds of either a red or green colour 
at Bray, and in the brown and purple shales of Carrick Mountain, 
county of Wicklow, and less distinctly and more rarely in the brown 
laminated shales of the northern coast of the peninsula of Howth, 
in the county of Dublin. ‘This species is less abundant than 
O radiata, and does not occur in dense masses like the latter, but 
usually as isolated and distinct branches scattered over the surface 
of the beds. It is more uniform in character than O. radiata, as, 
instead of radiating from a centre like that species, the branchlets 
are fan-shaped, and arranged in an alternating manner at regular 
distances upon a zigzag axis. Fig. 4, a, is a representation of this 
species, showing several branches of different sizes, as impressed 
upon a slab of green fine-grained laminated shale from Bray Head : 
* *Qn Anneloid Tracks in the Rocks of Bray Head,’ Journ. Geol. Soc. Dublin, 
vol. vii. p. 184, pl. 5, figs. 1-5; and ‘On the Zoological Relations of Bray Head 
and Howth, with an Account of the Fossils of Irish Cambria,’ Journ. Geol. Soe. 
Dublin, vol. viii. p. 68, pl. 7, figs. 1, 2. 
+ ‘The Genus Oldhamia, its Characters, &c.,’ Trans. Roy. Irish Academy, 
vol, xxili. (1858). 
