DR. HENRY WOODWARD ON EAST ANGLIAN GEOLOGY. 493 
The Red Crag. 
This deposit consists generally of dark red shelly sand, exhibit- 
ing false-bedding, and having a thickness rarely exceeding twenty- 
five feet. Sometimes the colour is yellow, brown, or grey. Seams 
of laminated clay are occasionally met with in it. The Red Crag 
is well shown at Walton-on-the-Xaze, Felixstowe, NValdringfield, 
Sutton, Ramsliolt, Butley, and other places. At Tattingstone, near 
Ipswich, at Sutton, and at Sudbourne, the Red Crag is seen in 
section superimposed upon the Coralline Crag, but the beds are 
more or less uncoil formable. Over the greater part of the area the 
Red Crag rests on the London Clay. 
Like the Coralline Crag, the Red Crag contains at its base a bed 
of derivative fossils which have been washed out of the London 
Clay, such as the teeth of sharks, Lanina elegans, Crabs, and some 
London Clay Mammalia, vertebrae of fishes, &c. Many of these are 
phosphatised. 
Among the more common Mollusca of the Red Crag may be 
mentioned : — 
Gasteropoda. 
Trophon ( Fusus ) antiguus 
,, „ r ontrarius 
Purpura tetragona 
„ lapillus 
Nassa granulata 
„ reticosa 
Buccinum undatum 
Natica catena 
,, multi punctata 
Littonna littorea 
Turritella incrcissata 
Lamkllibranchiata. 
Mactra arcuata 
,, oval is (sol id a) 
Tellina obligua 
„ crassa 
„ prcetenuis 
Lncina horealis 
Cardium edule 
„ angustatum 
My t this edulis 
Pecten opercularis 
Pectunculus glyc imer i* 
Echinodermata. 
Ecli inocyamus su ffolciensis 
Crustacea. 
Balanus crenatus, §c. 
The Red Crag is generally more ferruginous than the shelly sands 
of the Coralline Crag, hence its name. The Coralline was originally 
K K 
VOL VII. 
