64 THE DISPERSAL OF SHELLS. 



Other specimens of the same kind of water-beetle 

 with Sphcerium corneum attached have since been 

 obtained : Mr. C. Oldham found one, with a shell of 

 good size firmly clasping the extremity of one of the 

 front legs, in a pond at Woodford, Essex, in September, 

 1886 ; and I had the good fortune to catch a specimen 



FIG. 3. 



Spharhtm cornetttn upon the leg of a water-beetle {Dyttsc7(s); taken at West Bark- 

 with, Lincolnshire, and now in the Manchester Museum. 



with a shell upon the right front leg in a pond at West 

 Barkwith, Lincolnshire, in August, 1888 (Fig. 3).^ Mr. 

 W. H. Heathcote found another specimen with a 

 shell similarly attached at Farington, Lancashire, in 

 1889 ; and a further case, in which a small shell was 

 attached to one of the hind legs of the beetle, was 

 observed by Mr. Standen, in June, 1890, in a pond at 

 Birch, near Manchester. 



Some large water-beetles, kept by Mr. Norgate in 

 an aquarium, Mr. Darwin states, frequently had one 

 foot caught by a small fresh- water bivalve {S, 

 corneum f) ' 



i " Journ. of Conch," vi.(i888), 363 ; " Proc. Ent. Soc, Lond ," 



1888, p. XXXV. 



3 ''Nature," XXV. (1882). 529-30. 



