60 MOLLUSCA OF SOMERSET. 
any other fresh-water shell ; tenacity of life, unusually rapid 
propagation, the faculty of becoming attached by a strong 
byssus to extraneous substances, and the power of adapting 
itself to strange and altogether artificial surroundings, have 
combined to make it one of the most successful molluscan 
colonists in the world.” (H. Wallis Kew, in “ Dispersal of 
Shells,” p. 219). 
Jenyns Coll., Bath Museum. 
Bath Canal; Mrs. Oldroyd. 
River Avon, and Avon and Kennet Canal, Docks, ete. ; 
Cundall. 
In the Docks at Bristol; 7. G. Ponton. 
In the Avon; Letpner. 
Kennet and Avon Canal; Stoddart. 
Large specimens from the Kennet and Avon Canal, near 
Bath, one measuring 36 mm. by 144 mm.; H. Watson. 
UNIONID£. 
Unio PicTorRuMm, Linné. 
Common in rivers Avon and Brue. 
North. 
Naturalised in the Weston Rhine and the Lox Yeo; 
F. A. Knight. The specimens were brought from 
Langport. 
Kennet and Avon Canal, River Avon; Cundall. 
Bath ; Jenyns. 
Kennet and Avon Canal, near Bath; H. Watson. 
River Brue, near Glastonbury ! 
South. 
Taunton Canal; W. Gyngell. 
Var. compressa, Jeffreys. 
Bath Canal; Mrs. Oldroyd. 
Var. radiata, Moquin- Tandon. 
River Avon, Bristol; Cundall. 
Avon, Bath; Clark. 
Unio trumipus, Retzius. 
Frequent in the rivers Avon and Brue. 
North. 
Bath Canal; Bath Mus. Jenyns Coll. 
Bristol; Bristol Mus. Coll. 
