﻿AN HISTORICAL AND SYSTEMATIC REVIEW OF THE 

 FROG-SHELLS AND TRITONS 



By WILLIAM HEALEY DALL 



Everyone who has looked upon the numerous " triumphs of 

 Galatea," " births of Venus," and " processions of Neptune," in 

 European picture galleries, scenes dwelt upon by mediaeval painters, 

 has noticed the large, twisted, and variegated shells which are the 

 invariable wind-instruments of the lusty Tritons who form the chorus 

 around the sea-born deities depicted. These shells, the " Buccina " 

 of the ancients, became naturally in popular speech the " Triton- 

 shells," and finally the " Tritons " of the conchologist. Even at the 

 present day on many an Italian hillside the sonorous note of these 

 shells, blown by the peasants, serves to call the cattle home at dusk ; 

 and they may even be heard occasionally on the alien farms of New 

 England, in use for the same purpose, or as dinner horns. 



The elegant denticulation of the outer lip of these shells was copied 

 in ages past by the silversmith, and the special conventional type of 

 ornament thus derived has a name of its own, " gadrooning." 



Related to the Tritons is another group of shell-bearing mollusks, 

 variously known to eighteenth century conchologists as " frogs " 

 (from their tubercular ornamentation) or "purses" (from their 

 swollen oval form) and, since the development of a scientific nomen- 

 clature, by the more attractive names of Ranella or Bursa. 



The history of the classification of these shells is very complex and 

 has never been fully elucidated. The clearing up of some of the 

 obscurity which has enveloped them and the proposal of a more 

 modern and accurate system of classification for the two groups, is 

 the object of this paper; in which the author has availed himself of 

 the labors of many worthy predecessors, and, it is hoped, has made 

 some advance on their conclusions. 



I. Notes on Ranella and Its Allies 

 The first attempt definitely to segregate from the heterogeneous 

 Linnean Murices the group already popularly recognized under the 

 name of " Frog shells," or "Purses," was made in the anonymous 

 Museum Calonnianum in 1797. Here they were called Rana, a name 

 already in use for the batrachian referred to. The following year 



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