74 volutid.t:. 



is instituted upon the examination of the dentition of a single 

 species in each of these genera. That of Amoi'ia Tio-rieri^Grny, 

 has been supposed by some conehologists 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 niollusk, Favorinus albiis, Alder and Hancock.* 

 The dentition of Volutimifra Groenlandica 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 MitridiE to the Yolutida?, 

 merelj' upon the evidence of the armature of this one species. 

 The shell of Volutimil ro, has no intimate relationship with 

 Voluta^ but it is essentially a Mitrid. Graj' included a consid- 

 erable number of species of Marginellidai in his subfamily 

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

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

 discovered by Dr. P. Fischer in Valuta ^UKs/ca, which approaches 

 that of species of Marginellida'. 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 detinitive 

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

 far as known : 



f 1. Tooth ti'icus2>id, with large lateral points. 

 Cymbium, Melo, Volnta, Lyria. (PI. 2, 

 figs. 2, 3,4, 7.) 



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



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



3. Tooth multicuspid, very transverse. 

 [ Voluta mitsica. (PI. 2, fig. 6.) 



2. Formula : 1 • 1 • 1. Volutimitra. (PI. 2, fig. 8.) 



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



Yolutes are rarely collected with their animals, except when 

 they are accidentally thrown ashore after a storm. They have 

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

 •they are not found is that, like the Naticae, the}'^ burj^ themselves 

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



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



