52 THE DISPERSAL OF SHELLS. 



one of Li77t7icBa peregra^ all young-, together with seven 

 full-grown specimens of the little nautilus coil-shell 

 {Planorbis nautiletis). Mr. Cordeaux once noticed 

 minute molluscs among duckweed within the bill of a 

 wild duck shot by him, the bird having risen, no doubt, 

 in the very act of feeding. Confervoid vegetation, also, 

 seems likely to cling to birds, and Mr. Bridgman men- 

 tions having found masses of it literally teeming with 

 Planorbis nitidus, in company with a species of Valvata ; 

 after two or three weeks, however, the creatures, having 

 probably come to maturity, disappeared.^ It must not 

 be forgotten that parts of larger water-plants, to which 

 fry or ova may possibly be adhering, may occasionally 

 be carried by birds. The moor-hen, for instance, might 

 easily carry parts of plants in which its feet had be- 

 come entangled, and Mr. Norgate suggests that herons, 

 etc., are likely to carry them when flying off with 

 struggling eels hastily snatched from the mud and 

 weeds. Mr. Standcn mentions the shooting of suddenly- 

 flushed snipe, moor-hens, and wild ducks with weed 

 clinging to their feet, and he once flushed a heron which 

 rose with so large a quantity dangling from one of 

 its legs that its flight was considerably impeded. 

 Transportal of fragments of water-plants in this manner 

 probably happens quite commonly, for many kinds, as 

 Mr. Clement Reid^ has recently remarked, have ex- 

 tremely brittle stems, and finely divided or thin leaves 

 which on removal from the water collapse and cling 



1 W. K. Bridgman, "Zoologist," ix. (185 1), p. 3303. 



2 "Trans. Norfolk and Norwich Nat.Soc," v. (1892), pp. 278,^283-4 



