24 PROF. W. C. WILLIAMSON OX SOME UNDESCRIBED 



sea-line. The contours produced by many of tlie smaller 

 tributaries, where they united to form larger streamlets, 

 suggested to my mind the extreme probability that the 

 casts of such sculptured areas would, if found in any of 

 the older strata, be undistinguishable from many of the so- 

 called fossil " Fucoids " found in these strata. Working 

 carefully, I succeeded in obtaining a number of plaster 

 casts of these grooved surfaces, some of which are accu- 

 rately represented, through the aid of photography, by the 

 several figures 5-1 1 on Plate II., and figs. 12 & 13 on 

 Plate III. The leaf-like peripheral outline of some of 

 these figures has no significance, it being merely that 

 assumed by the flowing of the semi-fluid plaster of Paris 

 when poured upon the sand ; but it is otherwise with the 

 plant-like ramifications revealed on the surface of each 

 cast. Had such specimens been found on the inferior 

 surfaces of ancient flagstones, I have little doubt but that 

 they would have appeared in the pages of Schimper, and 

 other authors with similar views, as Palaeozoic Fucoidal 

 forms of plant-life ; anyhow their publication may benefit 

 some of our younger and more ardent palaeontologists, by 

 suggesting caution ere they give names and places in the 

 annals of Palseophytology, to objects which may be as 

 wholly inorganic as those which I have just described. 

 Nearly all the configurations of this kind which I 

 discovered at Llanfairfechan were of the same character 

 as those represented by figures 5-13 of my Plates. On 

 visiting the sands to the north of Barmouth during the 

 summer of 1884 I made diligent search, in the expectation 

 of finding there similar configurations. Products of tidal 

 action and drainage were not wanting, but to my surprise 

 those of the new locality were wholly difi'erent from what 

 I found on the Carnarvonshire coast. 



Pigs. 14 & 15 are photographs of casts made at Bar- 

 mouth, and represent the results of a double action, viz. the 



