RED CRAG. 
85 
also common species in the next higher division, but certain 
of the most abundant shells of the higher Red Crag seem to 
be entirely absent from Walton. Among these are the three 
species of Tellina, T. obliqua, T. lata, and T. pr(Etenuis, which 
often constitute a considerable part of the bulk of the Crag, and 
also the Nucula Cobboldim and several species of Leda found 
nearly everywhere in the upper Red Crag.^ Very little is yet 
known of the land fauna of the older portion of the Red Crag, 
but it is interesting to find that of four species of Helix (H. rysa^ 
H. lens, H, incarnata, and H. lactea), found at the base of the 
deposit at Walton, one is extinct, and the other three have an 
exclusively southern rsinge. A complete list of the fossils from 
Walton will be found in the Appendix. 
On the high ground at Beanmont (about 5 miles west of 
Walton) occurs shelly Red Crag, from which John Brown, of 
Stanway, obtained over 90 species of mollusca. The area of the 
outlier is about a quarter of a square mile, but there is now no 
section. The sand evidently belongs to the newer part of the 
Red Crag, for it contains several of the northern species missing 
at Walton. Red Crag also underlies later deposits on the hills 
between Little Oakley and Harwich. The outlier at Harwich, 
described by Dale in I704,t has now almost disappeared, though 
as late as 1872 Mr. Whitaker was still able to find a few fragments 
of shell at one spot on the top of the cliff. 
The other outliers in Essex, except those of Thaxted and Stoke 
mentioned below, are of little interest. They show disconnected 
outcrops beneath the newer deposits which cap low hills near the 
south bank of the Stour, between Harwich and Nay land. At 
Wrabness the Nodule Bed has been worked, and ferruginous sands 
with casts of shells were noticed by Mr. Whitaker as occurring 
at Mistley, Langham, and Boxstead. None of the sections now 
show shelly Crag, though such is mentioned by the Rev. W. B. 
Clarke J as found at Blackbrook Hill, 
North of the River Orwell the Red Crag covers a wide expanse 
of country, though commonly outcropping from beneath newer 
deposits along the valleys. The southern limit of the more 
continuous area follows an approximately east and west line, 
passing near Manningtree and Nayland, and bending northward 
and eastward to the south of Hadleigh, and then to Ipswich. 
Still further west an outlier at Sudbury shows that Crag un¬ 
doubtedly extended much further in that direction, and over¬ 
lapped most of the Eocene beds, till it rested directly on Thanet 
Sands, and in places touched the Chalk. Even 16 miles beyond 
Sudbury traces of Crag occur at Thaxted, in Essex, but there, 
and at Stoke, they are so mixed with glacial deposits that it is 
* See also Introduction to the Crag Mollusca .—Palceontographical Society, 
p. vii. 
t Phil. Trans., vol. xxiv. (No. 291), pp. 1568, 1.569. 
J Trans. Geol. Soc., ser. 2, vol. v. p. 362. (1840.) 
