COLUMBELLID^E. 101 



respectively. On the contrary, it is only necessary to examine 

 a large series of these species to become convinced that in most 

 cases these groups are connected by intermediate forms. Whilst 

 I cannot adopt them as subgenera on account of this want of 

 persistence of distinctive characters, yet such is the multiplicity 

 of species that retained as names of groups they may still serve 

 n useful purpose. Bellardi* has divided the fossil Columbellas 

 of Piedmont into groups designated as Nassiform, Mitriform, 

 Fusiform, etc., but I think the named groups of Messrs. Adams 

 preferable. Mo'rchf proposes the following classification : 



1. PYGM^BA, Humphrey. 



Subgenera, 1. NITIDELLA, Swn. 2. ALIA, Ad. 



2. PYRENE, Bolten. 



Subgenera, 1. ATILIA, Ad. 2. PYRENE, Bolt. 3. CONELLA, Swn. 

 4. DIBAPHUS, Phil. ( IMitridae). 



3. MlTRELLA, RisSO. 



Subgenera, t. ASPYRIS, Ad. 2. ANACHIS, Ad. 3. STROMBINA, Morch. 



He excludes Engina, on account of the dentition. The types 

 of Pygnuea, cited by him are typical species of Columbella, and 

 therefore Pygma?a may be considered a synonym 



I am only able to recognize a few genera, of which the principal 

 are Columbella, Engina and Columbellina the latter with some 

 doubt as to its characters being of generic value ; all the other 

 groups that have been proposed I place as Sections. 



The tamil} T has been monographed by Duclos, in Chemvs 

 Illustrations Conchyliologiques ; by Kiener, Coquilles Vivantes ; 

 by Sowerby, Thesaurus Conchyliorum, vol. 1, 1847 ; and by Reeve, 

 Conchologia Iconica, 1859. Since the latter date no revision or 

 catalogue of the species has appeared, whilst the number of 

 specific names has increased three times, or from 250 to about 

 750 nominal species. A large proportion of these five hundred 

 additional descriptions are unaccompanied by figures, so that 

 the labor of arranging the mass of material has been immense. 

 1 cannot hope to have determined the synonymy correctly in all 

 cases: I have done the best I could with the material at hand. 



* Mem. Acad. Turin., x, 225, 1849. 



f Jour, de Conchyl., 2d ser., iii, 260, 1858, 



