1852.] SEDGWICK ON THE LOWER PALEOZOIC ROCKS. 143 



In reply to some questions, arising out of this list, he writes as 

 follows : — " Of the above ten species all but two are common Dudley 

 species. One of these two seems to be very local, and the other is of 

 doubtful identification. All the corals, of which I have unfortu- 

 nately mislaid the list, are Wenlock species ; and several of them 

 have not hitherto been described from any lower beds. Several of 

 the above shells are also found in the Caradoc and Bala rocks ; but 

 some of them (as Euomphalus funatus — very abundant at May Hill — 

 and Hemithyris naviculd) are not. Lastly, I have not yet found in 

 your May Hill series, Leptcena sericea, or any of those common 

 Caradoc or Bala fossils which may be considered as characteristic, 

 because not also found in the Dudley and Wenlock series." Shall we 

 then, in such a case as this, strike oif the upper beds of the Caradoc 

 group, and pack them with the overlying group under some new 

 name, such as Wenlock-grits ? Provisionally I will accept what ap- 

 pears to be Professor Phillips's interpretation of such phsenomena; 

 viz. that the faunas of the two groups are not separated by any well- 

 defined geometrical line, but rather by an ambiguous boundary, near 

 which each fauna occasionally overlaps the other. But the above 

 facts do seem to show that the Caradoc group (the lowest Silurian 

 group ever made out stratigraphically by the author of the * Silurian 

 System') was the true connecting link between the Silurian and Cam- 

 brian series. 



Lastly, 1 may shortly notice another minute question, before I go 

 on to more general considerations. In 1846 I spent a few hours with 

 Dr. Davis in looking at the sections near Presteign ; and I expressed 

 an opinion that the Presteign limestone must be the equivalent of that 

 at Woolhope. I did not then remember the place assigned to it by Sir- 

 R. I. Murchison. Not long afterwards my friend Mr. Davis read a 

 paper before the Society *, in which he briefly alluded to, and contro- 

 verted, my verbally expressed opinion. In reply, I at the time 

 stated the grounds on which I had arrived at it ; viz. that the Pres- 

 teign limestone rested immediately on the Caradoc group, without 

 the intervention of any distinct argillaceous deposit ; and that the 

 same limestone was overlaid by an argillaceous deposit, which seemed 

 very well to represent the Wenlock shale. The position of this lime- 

 stone in the section seemed, therefore, to be exactly that of the Wool- 

 hope limestone. Mr. Davis also published a copious hst of fossils 

 from the Presteign limestonef ; and as they agreed generally with the 

 well-known Wenlock species, that fact was considered as almost con- 

 clusive in deciding the previous question. 



Never having traversed the beautiful Woolhope sections since 

 1834, 1 was anxious to revisit them during the past summer ; and in 

 an excursion of a few hours, I examined, in company with Mr. Lewis, 

 several of the quarries in the Woolhope limestone ; and obtained 

 from them the following fossils, which have been named by Professor 

 M'Coy :— 



Bumastus Barriensis (Wenlock). 

 Phacops caudatus (Wenlock) . 

 * Quart. Journ. Geol. Soc. vol. vii. p. 432. f Loc. cit. p. 437. 



