Chap. II.] 
CAMBRIAN FOSSILS. 
29 
Desirous of ascertaining whether these faint signs of primordial life 
might not lead to better evidences of a clear and recognizable fauna, I 
requested Mr. Salter, accompanied by a zealous young collector (Mr. John 
Ehind), to re-examine in detail those Longmynd strata in which it 
appeared likely that any other fossil could be detected. These researches 
brought to light several highly curious confirmations of the minute tracks 
or impressions having been made by Annelides. 
Let us here observe that the fine aggregation and unaltered condition of 
these sediments have permitted the minutest impressions to be preserved. 
Thus not only are the broad wave-marks distinct, but also those smaller 
ripples which may have been produced by wind, together with apparent 
rain-prints, as seen upon mud, and even cracks produced by the action of 
the sun on its half-dried surface. Again, as a further indication that these 
are littoral markings, and not the results of deep-sea currents, the minute 
holes left by the Annelides (fig. 1) are most conspicuous on the sheltered 
sides of the ripples in each slab. 
Surely, then, if many animals of a higher organization had existed in this 
ancient period, we should find their relics in this sediment, so admirably 
adapted for their conservation, as seen in the markings of the little Sea- 
worms, accompanied even by the traces of atmospheric action. 
In North Wales, where the same Cambrian rocks occur, no fossils, except 
such as are called Pucoids, have been detected in them. In Ireland, how- 
ever, where masses unquestionably of the same age prevail in the pic- 
turesque rocky tract to the S. and S.S.E. of Dublin, they contain two 
species of a supposed Sertularian Zoophyte, which, having been detected 
by Professor Oldham* in the purplish hard schists of Bray Head, received 
from Professor Edward Porbes the appropriate name of Oldhamia. 
Of these two Zoophytes (?), or perhaps Corallines (Stony Algals), one is 
here figured. It occurs in the hard rocks at Bray Head and Carrick Mac- 
Eeilly, Wicklow, but is most abundant at the last-mentioned of these 
places. Oldhamia antiqua (Poss. 3), 0. radiata, and a variety are care- 
fully delineated by Salter in Ramsay's 4 Geology of North Wales/ pi. 26. 
This obscure fossil, reminding the naturalist of the Sertularia, may have 
been really only a Seaweed. With the Oldhamia abundant traces of An- 
nelides, similar to those of the Longmynd, have also been found by Dr. 
E. Kinahan; and the same observer has attributed certain cylindrical 
cavities in these rocks to a boring Annelid, called by him Histioderma 
Hibernicumf . In the sequel, when treating of rocks and their age in the 
North-western Highlands, similar tubular cavities and infillings, also re- 
ferred to Worms, as described by Salter, will be mentioned. (See also 
Quart. Journ. Geol. Soc. vol. xv. p. 368.) 
* Then Local Director of the Geological Survey worm -like bodies of the Irish Cambrian rocks, by 
of Ireland, and now the able Director of the Geo- Mr. W. Hellier Baily, F.G.S., in the ' Geological 
logical Survey of India. Magazine,' Sept. 1865. Mr. Baily and Mr. Salter 
t Trans. Eoy. Ir. Acad. vol. xriii. p. 547. See a follow Dr. Goeppert in doubting the animal cha- 
clear account, with diagrams, of the zoophytic and racter of Oldhamia : so also Dana. 
