490 Prof. Sedgwick on the May Hill Sandstone, 



lists published in the ' Silurian System/ and in the descriptive 

 lists of the Cambridge Palaeozoic fossils by M'Coy. We added, 

 during our late hasty visit, only one new species, and it would 

 be idle for me to give many extracts from my note-book ; but I 

 will make one exception in favour of the quarries of Bird^s Hill 

 near Llandeilo, where there are several beds of limestone which 

 dip N.W., and are on the northern side of the Llandeilo saddle. 



In those ouarries are three or four bands of limestone marked 

 by lines of old and generally deserted works, and the calcareous 

 portions are more like the Coniston limestone and its associated 

 calcareous slates, than any other portions of the Llandeilo group 

 in the neighbourhood. From these beds we obtained the follow- 

 ing species : — 



1st quarry, the upper limestone band. 



Asaphus tyrannus, Orthis expansa. 



Orthis retrosistria. Trinucleus Caractaci, 



All exclusively Cambrian. 



2nd quarry, from the third band of limestone to the S.E. of 

 the former. 



Stenopora fibrosa. Spirifera hiforata, var. of fos- 

 Ptylodictija, n. s. sicostata (abundant). 



Orthis porcata. Leptagonia depressa. 



avellana. Leptcena sericea. 



elegantula (var. a). uralensis (?). 



parva. Bellerophon omatus (?) . 



testudinaria. Illanus. 

 callactis (Dal.). Ceraurus clavifrons. 



The species (like all the rest in this paper) are determined by 

 Professor M^Coy ; and he remarked, on the spot, that " we have 

 in this second quarry what I should call a good Bala list;'^ and 

 it perhaps deserves remark, that the list is wanting in some of 

 the very characteristic species of the Llandeilo flag, such as 

 Asaphus tyr annus and Ogygia Buchi, &c., which brings it still 

 closer to the fossil lists of Bala and Coniston. But it admits of 

 no doubt, that all the Bird's Hill beds are an integral part of 

 the Llandeilo group. Hence, without pretending to fix exactly 

 the place of this group, we have good palseontological, as well as 

 sectional evidence, to prove that it is deep packed in the Upper 

 Cambrian (or Bala) group, including under that term all the 

 rocks of the Cambrian series which arc above the Arenig por- 

 phyries and under the May Hill grits. 



On a review of all the facts above described, I can now affirm, 

 on fuller evidence than was given in my preceding paper (which 

 was based on the sections observed in 1853), that the scheme of 



