THE GEOLOGY OF PUFFIN ISLAND. 91 
the very highest littoral zone. The laminarian zone is 
represented by Trochus magus, Cyprea Huropea, Cyprina 
Islandica, &c.; the coralline and deep sea by Trichotropis 
borealis, Trophon clathratus var. Gunneri, Aporrhais pes- 
pelecani, Venus gallina var. Striatula, and Venus carina. 
Probably still more important a point is that so many 
zoological provinces are represented in this deposit; the 
Norwegian, Boreal, Lusitanian and Celtic provinces, all 
contribute to the Moel Tryfaen beds, and renders it 
almost impossible that they can have been deposited in situ. 
A comparison of the shells of this deposit with those of 
the unquestionably marine drifts of Wellington or South 
Lancashire, brings out features of marked difference; at 
Wellington a handful of good shells can be picked out in 
a few minutes, while at Moel Tryfaen you might sift for 
an hour and not see one; moreover, the lithological 
characters of the two sets of beds present important 
differences. It may be advisable to note in this connec- 
tion that so cautious a geologist as Mr. H. B. Woodward 
has recently contended* for the similarly remanzé nature 
of the shells of the Norfolk drifts. A further point that 
makes for the same conclusion is derived from the 
condition of the shells from the high level drifts of 
Ballymonduff and Caldbeck Castle, south of Dublin; + 
when recently examining the collection of shells from 
these deposits in the possession of the Rev. Maxwell Close, 
I was much struck by their resemblance to those of Moel 
Tryfaen, and especially by the fact that those from the 
greatest heights were always the more rolled and frag- 
mentary, obviously implying that they had been carried 
up by some such agent as ice 
* Proc. Geol. Assoc., vol. ix., p. 114. 
+ See Maxwell Close, Jour. Roy. Geol. Soc., Iveland, vol. iv., new ser, 
(1874), pp. 36 and 37. 
