and the Palaozoic System of England. 483 



2nd quarry — ^ 



Petraia uniserialis. Orthis parva. 



Ceraurus Williamsu elegantula (var a). 



Orthis protensa (in great turgida. 



abundance). Leptcena sericea. 



testudinaria. quinquecostata, 



flahellulum. 



This is a very characteristic Cambrian group, containing only 

 two species, which are common to the May Hill beds. 



The third quarry we had not time to examine in detail, but it 

 contained Leptmna sericea abundantly (a good Cambrian species, 

 never found by us in the May Hill or Wenlock groups) . 



Here (as in the former case) we are not able to define the place 

 of the Goleugod ridge by help of the sections. The country is 

 broken and faulted, and all the beds are highly inclined ; but 

 there cannot be a doubt that the ridge is, according to our no- 

 menclature. Upper Cambrian — a part of the upper Bala group. 

 It contains no quarry with a group of fossils like that of Penlan. 

 In the gravel over the rocks of the second quarry we, however, 

 found water-worn masses with casts of Pentamerus ohlongus, 

 which seemed to show that other May Hill beds were not far off. 



V. Quarries on the Hill of Mandinam. 

 The accompanying section, without pretending to any accu- 

 racy of detail, conveys, I believe, a correct idea of the relative 



Fig. 3. Mandinam Section nearly N, and S. 



Hill above Mandinam. S. 



N 



Quarry 



4 3 2 



1. Hills of Wenlock shale and Old Red Sandstone. 3. Beds with Cambrian fossils. 



2. Confused and mineralized beds. 4. May Hill group. 



position of the several groups. To the south are the escarp- 

 ments of the Old Red Sandstone, and of the Wenlock and Ludlow 

 groups. Then follows a valley in which the beds are dislocated, 

 mineralized, and penetrated by lead veins, which we had not 

 time to examine, as they are considerably to the east of the line 

 of section. Lastly follows the Mandinam ridge, which is very 

 fossiliferous, 



1st. Rocks near the top of the hill. 



Encrinurus punctatus. Leptana sericea (abundant). 



Orthis calligramma. quinquecostata. 



testudinaria. 



