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218 



Camulian Bccord of Science. 



VI. Pke Camijkian in Wai.ks. 



In the ])jist suiiiincr I was ciialilcd to s|kmkI a few days, 

 with the assistance of my friend, Mr. H. Tweeddale Atkin, 

 of Kgevton TarU, IJoek Ferry, in exaniinin^' the supjioscd 

 l*re-C' I'idirian roeks of Holyliead Island and An^iesey. 

 Fossils are very rare in these heds. As Sir A. (Jeikii; has 

 shewn, the ([iiart/itc^ of Holyhead is in sonu! ]»laees ]>erfo- 

 rated with evlindrieal wonn-hurrows; and in the niieaceons 

 shales there are lon^', cylindrical c /rds which may We 

 alj^ae of the Ljenns 7*^/A/v;r//7>/-(/</,and also hifnrcatinu,' fossils 

 reseml)lin<>' C/iotidrifrs, hnt 1 saw no animal fossils. I 

 liuve so far heen al)le to discover no ort^anic structure in 

 the layers of limestone associated with a])])arently heddcd 

 ser]>entine in the southern jtart of Holyhead Island. In 

 central Anglesey there are lenticular IhmIs of limestone 

 and dolomite associated with l*re-('and>rian rocks, which 

 Dr. Calloway regards as [»robal)ly e([uivalent to the 

 Tehidian of Hicks. In these there are obscure traces of 

 oruanic frau'inents ; and in one hed near IJodwi'oy; Church, 

 I found a rounded, lannnated hody, which may he an 

 in)i)erfectly preserved specimen of Cryptozoon or some 

 allied organism. The specimens ecjllected have not, how- 

 ever, heen yet thoroutihly examined. These, and other 

 })re-Cambrian deposits in (jrreat IJritain, corresjioutl in 

 their testimony with the Eo/oic rocks of North America, 

 as to the small numher and rarity of fossil remains in the 

 formations below the base of the I'ala'ozoic, and the 

 conse([uent probability that in these formations we are 

 a})proaching to the beginning of life on our planet. Mr. 

 Edward Greenly, F.G.S., of Achnasheaw, lUingor, is now- 

 engaged in a careful revision of the geological map of 

 Anglesey, and will give si)ecial attention to Pre-Cand)rian 

 fossils. He has already discovered, in rocks su})posed to 

 be of that age, organisms recognized by Dr. Hinde as 

 spicules of sponges.^ 



1 Jonrnal Geological Society, Nov., 1896. 



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