142 THE DISPERSAL OF SHELLS. 



Dr. Scharff tells me that he remembers having somewhere 

 seen an account of the finding of Helix ericetonnn alive 

 in alluvium. In December, 1880, Mr. Ashford win- 

 nowed out from amongst broken reeds and grasses more 

 than two thousand shells of the young of Succinea putris, 

 which had been swept from their winter moorings on 

 the vegetation bordering the Avon by a recent flood, 

 and left in the meadows near Christchurch ; the greater 

 part, if not all, however, it is said, had " fallen a prey 

 to tiny but voracious larvae, probably of the smaller 

 coleopterous insects." ^ 



As instancing possible or probable results of rivcr- 

 transportal we may advert to statements given by Mr. 

 W. G. Binney in the second supplement to his famous 

 work, previously quoted, on the land-shells of the United 

 States and adjacent territories.'- Helix strigosa, it is 

 stated, a widely distributed Central Province group of 

 forms, ranging to the westward to the Sierra Nevada 

 and Cascade Mountains, passes the latter even to the 

 Pacific Ocean, but the author doubts whether it is " really 

 an inhabitant of the Pacific Region," the specimens col- 

 lected from time to time west of the Cascades in 

 Washington Territory and Oregon being possibly " in- 

 dividuals brought down by the Columbia River from 

 the east of the Cascades, or colonies descended from 

 such." Mr. Hemphill, he states, first called his atten- 



' C. Ashford, "J ourn. of Conch.," iii. (1881), pp. 195-6. 



- " Terrestrial air-breathing MoUusks," second supplement to 

 vol. v., pp. 26-8, 32, 39 : Bulletin Museum of Comparative Zoology, 

 Harvard College, vol. xiii. No. 2. 



