DISPERSAL BY MAN. 225 



distinguishable from specimens, in the British Museum, 

 collected in Cuba, St. Thomas, and St. Croix. The 

 Rev. A. H. Cooke, in 1882, mentioned having taken 

 the animal abundantly in the Victoria regia tank in the 

 Royal Gardens, and I hear from Mr. J. B. Davy that 

 Mr. Watson, the assistant curator, has seen it in " the 

 lily-housCj formerly called the Victoria regia house.-" 

 Probably the creature is not confined to any particular 

 water within the gardens. The tank in which it was 

 originally found is said to have been exposed in the open 

 air to the inclemency of our winters, and this is not the 

 case either with the lily or Victoria regia tanks, both of 

 which are in warm houses. Mr. Cockerell, in 1885, 

 reported that the species was *' still abundant in a 

 water-lily tank at Kew." In 1890, specimens were 

 obtained by Mr. Grocock and Mr. Jenkins from the 

 Royal Botanic Society's gardens. Regent's Park. They 



Britain. According to Canon Norman the description in the 

 Linnean Transactions of the "■Bulla rivalis''^ of Maton and 

 Rackett, 1804,— said to have been found by Mr. James Hay in 

 Hampshire — sufficiently accords with P. acuta (to which shell in- 

 deed jMoquin-Tandon had assigned it as a synonym), and he 

 remarks that Montagu, who was well aware that Bulla rivalis was 

 a common West Indian shell, did not question the discovery of 

 Mr. Hay. " Physa aciita^' is given also in Captain Brown's 

 "Illustrations," 1844, as having been "found in Anglesea, Wales, 

 and first identified as British by J. Sowerby, Esq.," but it is now 

 stated that the shells, in this case, ought to have been referred to 

 a variety of our common British species Physa foniiiialis. See 

 Maton and Rackett, ''Trans. Lin. Soc," viii. (1807), p. 126; T. 

 Brown, " Illustrations," ed. 2,(1844), P- 3° ; Forbes and Hanley, 

 " British Mollusca," iv. (1853), pp. 145-6 ; A. M. Norman, "Ann. 

 and Mag. Nat. Hist.," (3),vii. (1861), pp. 1 15-16. 



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