OF CONCIIOLOGY. 5Y 



quires still further reduction. Coins, as we have recently 

 determined by the examination of the teeth of a species allied 

 to the type, Fusus colus Lam., belongs to the Fasciolariidte, 

 Bullia, Nassa^ Phos, and their allies, included in the group by 

 Gray, have been very properly separated by H. & A. Adams 

 'and Carpenter. Cassidiih's and its allies, included by H. & A. 

 Adams, is properly separated by Gray and Carpenter. Certain 

 Columbellidte included by Gray and Carpenter, are properly 

 separated b}^ H. & A. Adams. The Columbellidte have, in 

 their unarmed rhachidian and claw-shaped lateral teeth, a pecu- 

 liar and singularly constant type of lingual dentition* which 

 forbids the dismemberment of the group on account of diifer- 

 eiices in the shape of their opercula. 



We have then remaining to the family the genera 3Iurex, 

 Tt/phis, Trophon, Neptimca, Strovihella, Clavella, Pisania, 

 Pallia, Tritonidea, Engina, Metula and Euthria, none of which 

 have been referred to any other family by the most recent 

 scientific authors. Among these, however, we find two dis- 

 tinct types of lingual dentition. 



1. In Murex and the two genera following, the lingual rib- 

 bon (plate 8, fig. 3,) is very small ; the rhachidian tooth is 

 thick and solid, somewhat like a section of a prism, with the 

 denticles projecting from the anterior edge of the convexity of 

 the upper surface ; while the lateral teeth are always simple, 

 with but a sin2:le dentiform lobe arisino- from the base of at- 

 tachment. 



2. In JVeptunea and the six genera following, the lingual, 

 ribbon (plate 8, fig. -i,) is much larger and broader in propor- 

 tion ; the rhachidian tooth is flat and lamelliform, with denti- 

 cles arising directly from the anterior margin ; while the lateral 

 teeth are each armed with at least two strong dentiform lobes. 

 This dentition closely resembles that of the Buccinida?. 



There is thus a far greater difterence between the dentition 

 of the Murex -gYonp, and of the JVcptiDiea-gvoni) than between 

 that of this latter group and that of the Buccinidie. A¥e 

 therefore propose to restrict the limits of the family Muricidaa 

 to the genus 3Iwex and its allies, and to place the Neptunese, 

 etc., in the family Buccinidas a,s a sub-family Neptuniinas. 



The dentition of Metula and Enthria is as yet unknown, so 

 that their true place remains uncertain. 



After so wholesale a depauperization of the family Muri- 

 cidre, we can do no less than endeavor to make amends by 

 seeking for the genera which, though properly belonging to 

 it, may have been wrongly placed in other families. 



*See Moerch's investigations upon the lingual teelh of the Columbellidae. 

 Journal de Conchyliologie, VII., 1858, p. 2o4. ; 



