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POPULAR SCIENCE REVIEW. 
the upper part of the series ; here are found new species 
of Paradoxides and Conocoryphe , as well as fragments of several 
other fossils. Numerous markings are seen also on the surfaces 
of these and the underlying beds, similar to those described by 
Dr. Torell from Scandinavia, under the name of Eophyton. 
These were supposed by him to be land plants. Besides these 
numerous large so-called fucoidal markings are also frequently 
found. Whether any of these can be safely attributed to land 
or marine plants, must still be a matter of doubt, as no indica- 
tions of true structure have been found in them. The upper 
beds of this group are grey grits and flags, and these also 
contain a special fauna. There can be no doubt that the Solva 
group represents the main portion of the Harlech- grit series 
as known in Merionethshire, and also probably of the Long- 
mynd rocks. That there are some beds in those areas which 
may be considered contemporaneous with the Caerfai group, is, 
as I have already stated, probable ; but I believe that the 
St. David’s area was depressed at an earlier epoch than either 
of those, and therefore that it probably contains a series 
unrepresented there. I am inclined to think, however, that 
the lower beds of green grits and slates at Llanberis are 
nearly on the horizon of the Lower Caerfai rocks at St. David’s. 
The rocks at Bray Head, in Ireland, appear to be more nearly 
contemporaneous with, the Solva group than with the earlier 
beds. The St. David’s fossils have not as yet been discovered 
in any of the other areas. Annelids and a doubtful trilobite, 
Palceopyge , were, however, found years ago by Mr. Salter in 
the Longmynd rocks ; and annelids and the curious fossil, 
Oldhamia, have been found in the Bray-Head rocks. 
Grey Rocks, with Paradoxides aurora. 
Grey, purple, and red Rocks, with Paradoxides solvensis, 
Conocoryphe solvensis , &c. 
Yellowish Grits, Sandstones, and Flags with Paradoxides 
Harknessii, Plutonia Sedgwickii, and also Popliyton , 
large Fucoids, &c. 
Menevian group . — This name was given by the late Mr. 
Salter and myself in 1865, to a series of beds found to contain 
a very important fauna new to this country at St. David’s. 
Though there is a gradual passage from the beds of the Solva 
group into these (as shown in Sect. 1, p. 308, and in Pis. VII. and 
VIII.), in general appearance the rocks differ considerably from 
those in the other Lower Cambrian groups. This may be due to 
the combined influence of deeper water, and the presence 
of a greater abundance of animal and vegetable life; the 
O 1 
r Upper, 
150 ft. 
Middle, 
1500 ft. 
Lower, 
150 ft. 
