Proceedings. 19 
The last area of Tremadoc Slates to be described was dis- 
covered in 1894 by Miss E. G. Skeat and the writer of this 
paper, and lies to the S. of the town of Carmarthen in South 
Wales. The beds strike nearly due E. and W., they dip due 
S. under the O. R. S., which in this part of Wales overlaps the 
beds immediately underneath it, and rests unconformably on 
the older Silurian rocks. 
Only a few exposures of the slates have been found, for the 
country here, as at Tremanhir and St. David’s, is covered in 
places with a thick coating of drift. 
The shales are fine-grained and finely bedded, of a blue-grey 
colour. They weather arich yellow or brown, and are often 
iridescent, from being covered with a film of iron-oxide; with 
the shales are occasional bands of micaceous sandstone. 
The fauna up to the present obtained from these beds is 
small, and nearly all are new species, so that the difficulty of 
correlating these beds with those of other areas is great. 
The following is a complete list of the fossils at present 
obtained :— 
Parabolinella, n. sp., cf. rugosa, Brogger. 
Peltura punctata, n. sp. 
Ogygia marginata, n. sp. 
Erinpys sp. 
Orthcceras sp. 
Orthis sp. 
Modiolopsis sp. 
Let us now consider the place of these beds in the strati- 
graphical succession, and also their relative age with regard to 
each other. 
‘We will note first their position in the stratigraphical 
succession. Among the trilobites recorded from each of the 
districts, we have representations of two types :— 
(1) Those trilobites which have many body-rings and a small 
tail, which are characteristic of the Primordial Fauna 
(Cambrian) ; 
(2) Those trilobites which are compact in form, whose hinder 
segments have become fused together, and which have 
c2 
