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XXX VIII. 
ON PUCKSIA MAC HENRYI, A NEW FOSSIL FROM THE 
CAMBRIAN ROCKS OF HOWTH. By PROFESSOR 
SOLLAS, D.8Se., LL.D., F.R.S. 
(COMMUNICATED BY PERMISSION OF THE DIRECTOR-GENERAL OF THE 
GEOLOGICAL SURVEY.) 
[Read Decemper 19, 1894; Received for publication January 15; Published 
Frepruary 15, 1895.] 
Tue barrenness of the rocks of Howth and Bray in organic 
remains is rendered rather more than less surprising by the un- 
doubted fact that living organisms were not entirely absent from 
the seas in which these rocks were deposited. This is proved by 
the occurrence in rare localities of such problematical forms as 
Oldhamia, and still more conclusively by the innumerable worm- 
borings, which traverse the brilliantly coloured sandstones of the 
cliffs, near the Needles. 
Worms naturally suggest the contemporary existence, in some 
place or other, of a great variety of lower forms of life both 
animal and vegetable; but of the remains of these scarcely any 
direct indications have as yet been discovered in our district. 
The nature of the rocks is generally not ill-fitted for their 
preservation. Fine grained slates which have retained such deli- 
eate markings as those of Oldhamia, might fairly be expected to 
present us with some remains of the skeletons of graptolites, 
brachiopods, or trilobites, if any of these had lived in association 
with Oldhamia. That no trace of these or any other organisms, 
except worms, has hitherto been discovered, in spite of the most 
careful searching, seems open to only one explanation: and one 
is led to suppose that the Cambrian sea around Dublin, was for 
some reason or other, during the greater part of its existence, an 
almost lifeless area. 
The fewer the fossils, the more strenuous must be our search for 
them; and I have now to describe a curious structure, which I 
SCIEN. PROC. R.D.8., VOL. VITI., PART IV. Z 
