﻿124 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



subsequent synonymy becomes very complex from Morch's attempt 

 in 1852 (in which he was followed by Henry Adams in the ' Genera 

 of Recent Mollusca ' in 1853) to revive the prelinnean names of 

 Klein. Morch made a second attempt in 1877 but the rules of 

 nomenclature bar out any such arrangement. Our readers may fol- 

 low, in the synonymy with which this article concludes, the fluctua- 

 tions of opinion as to the names to be used in this group. 



In 1853 Gray, following Troschel (1852), definitely separated the 

 Tritons and Ranellas from the Muricid®, on account of their Tamio- 

 glossate radula, a course which has since been universally adopted. 



In 1863 Troschel took up the group and finding well-marked dis- 

 tinctions between the characteristics of the radula in, on the one hand, 

 Bursa, Aspa, and Lampas (Schumacher), and, on the other, Tri- 

 tonium (Link), Distorsio, Cymatimn, Simpulum, Guttumium, 

 Cabcstana, and Apollon, — he separated the group into two fam- 

 ilies, Ranellacea and Tntonacea, and each of these into several 

 genera. In this course perhaps too great a value was assigned to 

 minor features of the radula, but it remains certain that two well- 

 marked groups are extant in the assembly. Gray divided the Tri- 

 tonidcc into four subfamilies based chiefly on differences in the 

 operculum. We may at least divide them into two subfamilies, each 

 containing several minor groups, utilizing for this purpose the char- 

 acters of shell, dentition, and operculum, besides those of the larval 

 stages where they are known. 



In 1 88 1 Jousseaume attempted a new and purely conchological 

 classification, not without merit, and the last discussion of importance 

 is by Kesteven in 1902, where valuable data as to the larval shells are 

 put on record, and a classification by unnamed conchological groups 

 is attempted. This kind of an arrangement however is less con- 

 venient than one in which the group is not only recognized but is 

 given a name. The difference is analogous to that between poly- 

 nomial and binomial nomenclature. Sometimes it happens that, in 

 very large groups the clustering of certain forms around certain 

 others, all of which are connected by intermediate gradations, may be 

 expressed in this manner ; but in most cases it would seem that it is 

 less inconvenient to ignore such nebular groups altogether, so far as 

 the nomenclature is concerned, or to give them sectional names by 

 which they can be handled easily. 



The last attempt at an arrangement of the family is by M. Maurice 

 Cossmann, in his Essais de Paleoconchologie Comparee, v, Decem- 

 ber, 1903. In this the author returns to the ancient confusion caused 

 by regarding the varices and their position as a fundamental char- 



