74 VOLUTID^. 



is instituted upon the examination of the dentition of a single 

 species in each of these genera. That of Amoria Turneri, Gray, 

 has been supposed by some conchologists to be an error on the 

 part of that very able but exceedingly hasty and careless 

 observer, as it appears to correspond very closely with that of a 

 nudibranchiate mollusk, Favor inus albus. Alder and Hancock.* 

 The dentition of Volutimitra Gfroenlandica is similar, but with 

 the addition of lateral teeth. We are not willing to remove a 

 number of tropical species heretofore classed in this genus along 

 with this single boreal one, from the Mitridsv to the Yolutida*. 

 merety upon the evidence of the armature of this one species. 

 The shell of Volutimitra has no intimate relationship with 

 Valuta, but it is essentially a Mitrid. Gray included a consid- 

 erable number of species of Marginellidffi in his subfamily 

 Yolutimitrina, but these were excluded by II. and A. Adams. 

 It remains to specify an entirely different type of dentition, as 

 discovered by Dr. P. Fischer in Valuta musica, which approaches 

 that of species of Marginellidae. It is evident that such diversity 

 in the few tongues examined must be fatal to the classification 

 of the group upon this character, until we shall have determined 

 the dentition of every species before assigning to it a definitive 

 position. Fischer thus tabulates the dentition of the family, as 

 fa r as known : 



f 1. Tooth tricuspid, with large lateral points. 

 Cymbium, Afelo, Valuta, Lyria. (PI. 2, 

 figs. 2, 3,4, 7.) 



1. Formula : 1 0. -j 2. Tooth unicuspid, with concave base. 



Amoria. i PI. 2, fig. 5.) 

 3. Tooth multicuspid, very transverse. 

 L Valuta innsica. (PI. 2, fig. G.) 



2. Formula : 1 1 1. Volutimitra. i PI. 2, fig. 8.) 



This last form I place in Mitricke, as explained above. 



Volutes are rarely collected with their animals, except when 

 they are accidentally thrown ashore after a storm. They have 

 therefore l.een said to live in the depths of the sea. The reason 

 they are not found is that, like the Nat iea>. they bury themselves 

 under the surface as soon as the water falls and the sand is left 



* Morch, Jour, de Conch., xv, 241, 1867. 



