132 



SHELLS AND SHELL-FISH. 



our investigation in the mitres. Whether we view the 

 family Volutida as a whole, or contemplate separately 

 each of its divisions, whether large or small, we shall 

 find their variation uniformly harmonising with what 

 has been seen in the Muricidce and the Turbinellidce, 

 a fact which every one will perceive, on investigating 

 the following table, which is also sufficient to furnish the 

 clue even to the analogies of the sub-genera. 



General Analogies of the VOLUTID^. 



STROMBID*. MARGINELLTN^E. Scaphclla. Mitrella. NASSINJL. EBURNIN.E. 



(119.) The three aberrant divisions of the volutes, 

 namely, the OLIVIN^E, the ANCILLARIN^E, and the MAR- 

 GELLINJE, must be dismissed in a few words. The minor 

 variations in each are very few, and will be found in 

 the systematic arrangement. The genus Mitrella leads 

 us immediately from the mitres to the olives ; where, 

 as in Harpula, the plaits upon the pillar cover the whole 

 length of the inner lip : the foot of the animal is ex- 

 cessively large, and sufficiently dilated to fold over the 

 greater part of the shell ; but the mantle is not lobed. 

 The first genus is Lamprodoma *, which chiefly differs 

 from Mitrella in having the channeled suture so uni- 

 versal among the olives. This leads to the typical 

 genus Oliva., wherein the majority of the species are still 

 arranged. Scaphula, by its thick undefined spire and 

 ventricose body-whorl, is a complete prototype of the 

 melon volutes, and prepares us for Hiatula, in which the 

 characters of Oliva, Scaphula, and Ancillaria are com- 

 bined. The circle is then closed by those small species 

 arranged under the genus Olivella, wherein the base of 



* Lamp. Olivella, Zool. 111. ii. pi. 40. fig. 1. 



