731 A. E. Verrill—The Bermuda Islands. 319 
it had become abundant and injurious over a large part of the Main 
Island. Its ravages soon attracted the attention of the Board of 
Agriculture. Finally a prize was offered by them for the best essay 
on this snail. Five of the resulting essays were published together 
in pamphlet form.* 
At the present time this snail is exceedingly abundant over all of 
the Main Island and the other islands connected directly with it, 
being carried about by carts and in various other ways, and with 
merchandise of many kinds. It is very prolific and has very few 
natural enemies. It feeds on a great variety of plants, including 
76 
Figure 76.—Spiral Snail (Rumina decollata) ; a, animal expanded ; 6, shell ; ‘both 
natural size. Figure 77.—Subulina octona; x2. Figure 78.—Opeas Swif- 
tianum; x24. Figure 78a.—Cecilioides acicula ; after Binney. 
nearly all cultivated crops. Hand picking is practised to a large 
extent and great quantities are destroyed, but the total number 
seems to be constantly increasing. 
The Tropic Bird has learned to eat it at certain times, but whether 
to any great extent is not known. (See p. 680.) Probably the great 
* « Wive Essays as furnished to the Board of Agriculture in response to an 
advertisement offering prizes for the descriptions of and the History of the 
Spiral Snails, and the most efficacious, expeditious, and economical methods to 
effect their extermination.” Printed by Gregory V. Lee, Queen’s Printer, Ham- 
ilton, Bermuda. (No date.) 
The Essays are by the following authors: 1, by the Rev. W. G. Lane. 2, 
by Theophilus Roach. 38, by Morris A. M. Frith; appended to this are copies 
of letters from J. M. Jones and John T. Bartram, giving facts as to the earliest 
date, 1876, of the introduction of R. decollata, as indicated by finding a single 
specimen. 4, by O. T. Middleton. 5, by Miss Annie Peniston, contains many 
facts as to the date of introduction and rate of diffusion. 
