104? CARYCHIID,E. 



on our coasts, which are closely allied, have been placed 

 by some conchologists in different genera and removed 

 from Melampus. The classification of all objects of 

 Natural History is to a great extent artificial ; and the 

 larger groups are more difficult to define than species. 

 I prefer reducing the number of these divisions, and 

 thus simplifying the nomenclature, unless characters of 

 sufficient importance can be found to distinguish them. 

 Lamarck's name Auricula has precedence of Me- 

 lampus by many years ; but the former name has been 

 appropriated to shells, mostly tropical, of which the 

 Voluta auris-Midae of Linne is the type. The outer lip 

 in Auricula has a thick and somewhat expanded edge. 

 Conovulus of Lamarck is two years later than Melampus,. 

 and is a mere synonym. Phytia and Alexia have been 

 proposed by Gray and Leach for M. myosotis ; and 

 Ovatella, Iaminia, and Leuconia of Bivona, Leach, and 

 Gray have M. bidentatus for their type. 



1. Melampus bidenta'tus"*, Montagu. 



Voluta bidentata, Mont. Test. Br. Suppl. p. 100, t. 30. f. 2» Cmiovwlus 

 bidentatus, F. & H. iv. p. 191, pi. cxxv. f. 1, 2» 



Body white, of a frosty or reticulated texture: mantle 

 having its edge sometimes slightly protruded beyond the mouth 

 of the shell : head furnished with a curved lobe on each side : 

 snout narrow, cloven in front : tentacles very short, compressed, 

 variable in shape : eyes proportionally large, but dull, placed 

 a little behind the tentacles, at their base : foot oblong, squa- 

 rish in front and rounded behind ; when in action it is divided 

 across at about one-third of its length, so as to form two 

 creeping disks and to produce a wave-like or alternate motion : 

 respiratory orifice oblong and large. 



Shell spindle-shaped, usually rather solid, nearly opaque, 

 glossy : sculpture, none except just below the suture, where 

 there are slight and close-set longitudinal striae, scarcely 

 visible to the naked eye : colour ivory-white : epidermis thin 



* Two-toothed ; properly bidens. 



