254 THE FOEx\MINIFERA 



many of the specimens. The commonest genus in 

 point of numbers in this rock is SjririUina (see fig. 

 27), and the particular form is not so very different 

 from a species now often met with in shallow water 

 off the British coasts. The other genera accompany- 

 ing the S]jiriUince- of the Upper Cambrian are 

 Lagena, Nodosai-ia, MarginuUnd, and Cristellaria. 



Fig. 27. — Spirillina Eock ; Upper Cambrian, 

 Malverns. X 36. 



In the Ordovician system the shales above the 

 Bala limestone at Guildfield, near Welshpool, have 

 been recorded as foraminiferal by W. Keeping. 



In the Silurian system the Llandovery beds of 

 Cwm Symlog have yielded to J. F. Blake Dentalina 

 communis and to W. Keeping Textularia, Dentalina, 

 and (?) Botalia. 



From the Woolhope Limestone of the Malverns 

 H. B. Brady obtained four species of Lagena, which 



