NORTHUMBERLAND AND DURHAM. 169 
Both these were adult males, pale brown above, ashy grey below, 
the colours somewhat abruptly separated. The tail constricted 
at the base, quadrangular for two-thirds of its length, then 
flattened. 
A chesnut-coloured variety was described by Mr. Jenyns as 
distinct, under the name of S. castaneus, but its specific distinc- 
tion was afterwards abandoned (A. N. H., I. 424; II. 43; VII. 
267). 
S. tetragonurus is abundant everywhere in our district. 
(SUB-GENUS, HYDROSOREX, Duvernoy.) 
3. 8S. FopiENs, Gmelin. Water SHREW. 
Sorex fodiens, Jenyus; Man. Brit. Vert. 18; A. N. H., I. 
425; Bell, Brit. Quad. 115; Penn. Brit. Zool. I. 126; 
S. bicolor, Shaw; Crossopus fodiens, Wagler. 
The sub-genus Hydrosorex is distinguished from Amphisorex 
by having only four lateral incisors in the upper jaw, of which 
the first two are equal, the third smaller, and the fourth, rudi- 
mentary, instead of presenting a gradually diminishing series. 
The tips of all the teeth are a little coloured. 
The water-shrew is tolerably plentiful in both counties; 
“‘ Cockerbeck, Darlington,’ W. Backhouse, ‘‘ Castle Eden,” Rev. 
H. B. Tristram, “ Newcastle,” H. 7. M., “‘Twizell,” P. J. Selby, 
are localities widely apart, and sufficient to show its general 
distribution. 
The dentition of this species is mid. inc. 3; lat. ine. 4, 4; 
molars $, 4; total 718. 
4. §. ciniatus, Sowerby. Oarep Surew. 
S. remifer, Yarrell; Jenyns, Man. Brit. Vert. 18, A.N. H., 
Webs elke pk Genie 5 
This species has generally been referred to the S. remifer of 
Continental authors, but the identification is extremely doubtful, 
the English species being much smaller than the true remifer. 
Mr. Jenyns, in some of his communications on the species of 
this genus, doubts the specific difference of this from the last 
