IV. 
LIST OF LAND AND FRESH-WATER MOLLTJSCA OBSERVED IN 
HERTFORDSHIRE. 
By Ada Selby ; 
J. Gwyh Jeffreys, LL.D., F.R.S., F.L.S., F.G.S.; 
W. S. A. Griffith, F.R.C.S. ; 
and Alfred T. Brett, M.D. 
Compiled by J. Hopkinson, F.L.S. 
Bead at St. Albans , 10 th January , 1884. 
The species and varieties of Land and Fresh-water Mollusca in 
the following list have been collected or observed between Watford 
and Badlett, and in the beech woods between Aldbury and Ashridge, 
near Tring, by Miss Selby in 1879 and 1880; in the neigh¬ 
bourhood of Ware by Dr. Gwyn Jeffreys during his residence at 
Ware Priory from 1870 to 1880; in the neighbourhood of Sand- 
ridge near St. Albans by Mr. Griffith in 1875 and 1876; and at 
Watford, chiefly in the Colne and the ditches and meadows near 
the river, by Dr. Brett in 1852. 
The surnames of the observers are appended to their records, and 
in the sequence and nomenclature of the species the Conchological 
Society’s ‘ List of British Land and Fresh-water Mollusca, 1883,’ is 
followed. 
COHCHIFERA. 
IA MB ILIBRANCHIA TA. 
SPHiERIIDiE. 
Sphcerium corneum (L.). — Watford, common ; Selby ; Brett. 
Sandridge, common in every pond; Griffith. Ware ; Jeffreys. 
Yar. flavescens, Macg. — Sandridge; Griffith. 
S. lacustre (Mull.). — Ware ; Jeffreys. 
Bisidium amnicum (Mull.). — Brocket Hall lake, and in River Lea 
above and below the lake, plentiful; Griffith. 
P. fontinale (Drap.).—Watford ; Brett. Brocket Hall lake ; 
Griffith. Ware; Jeffreys. 
P. pusillum (Gmel.).—Watford; Brett. Ware; Jeffreys. 
P. nitidum, Jenyns.—Watford; Brett. Ware ; Jeffreys. 
P. roseum , Scholtz.—Ware ; Jeffreys. 
Mmmivm. 
XJnio pictorum (L.).—Ware ; Jeffreys. Yar. compressa , Jeffr. — 
Ware ; Jeffreys. 
Anodonta cygnea (L.). — Reservoir-stream near Radlett; Selby. 
Watford ; Brett. Brocket Hall lake, very abundant but Dot large, 
the largest specimen measuring 4iins. in length ; Griffith. Ware ; 
Jeffreys. 
