PART II. CHAPTER XIV. 



175 



Older Pliocene Strata English Crag. 



between the red crag and London clay ; and the strata of the 

 upper and lower crag are unconformable one to the other, as in 

 the section represented in the annexed diagram, which I have 

 myself examined. 



Fig. 128. 



a. red craj 



Section near Ipswich, in Suffolk, 

 b. coralline crag. 



c. London clay. 



In the places here referred to, the coralline crag varies in 

 thickness from fifteen to more than twenty feet, and the red crag 

 is often much thicker. 



Amongst upwards of 400 species of testacea found in the 

 crag, there are many common to both divisions ; but some, 

 which are very abundant in the red, have never been met with 

 in the coralline crag ; as, for example, the Fusus contrarius 

 (Fig. 129.), and several species of Nassa and Murex, (see Figs. 



Fig. 129. 



Fossils characteristic of the Red Crag. 



Fig. 130. 



Fig. 131. 



Nassa granulata. 



Fig. 132. 



Fusus contrarius. 



Murex alveolatus. 



Cyprcea coccinelloides. 



130, 131.), which two genera seem never to have been disco- 

 vered in the lower crag. On the other hand, scarcely any corals 

 have been found in the red crag. These abound in the inferior 

 division, and some of them are of a globular form, and belong 

 to the genera Theonoa (Lamoroux), Cellepora, and a third to 

 Fascicularia, which is of very peculiar structure, unknown in 

 the living creation. (See Fig. 133.) 



