110 SHELLS AND SHELL-FISH. FART 1. 



in two respects; — first, to show that this shell was the 

 prototype of the genus Volutilithes ; and, secondly, to se- 

 parate it from V. Scapha. The next type we place after 

 angulataisfulgetrum, with which, also, comes magnifica. 

 Now, the complete glazing of angulata (which shows 

 the great size of the animal's mantle) is partially car- 

 ried on to fulgetrum, which Mr. Sowerby thus describes : 

 — " The left lobe of the mantle of the animal must have 

 been very large, since the columella lip is extended so as 

 to cover half of the lower volution." And that this 

 shell exhibits a further affinity to the slender spire and 

 angulated body-whorl of angulata, is evident on the 

 same testimony.* Evidence of this sort, from an un- 

 prejudiced writer, is the very best that can be produced, 

 since it is given without any idea of the use it may be 

 applied to. 



(100.) Our arrangement of the Lamarckian volutes, 

 being thus founded solely upon affinity, would seem to 

 require no additional corroboration ; but beneath the sur- 

 face of this beautiful chain of relationship, lies another, 

 even more interesting, which can be only brought to 

 light by comparing the analogies, which all these vari- 

 ations in form present among themselves. These re- 

 semblances are so remarkable, that we shall now enter 

 upon them very fully. To do this in all cases, even 

 were it possible, might be tedious ; but in the present 

 instance it is almost unavoidable, inasmuch as we desire 

 that our theory on the laws of representation among the 

 Testacea should stand or fall according to the success 

 or failure which may attend their exposition in this and 

 the two preceding families. 



(101.) The principles of natural classification, so fully 

 explained in the second volume of this series, and the 

 innumerable proofs taken from every class of vetebrated 

 animals that have been brought forward in the succeed- 



* y\ Julgetriim "is easily distinguished by its acuminated papillose 

 spire, and by the obtuse angle on the upper part of the last volution.'' — 

 Sow., in Tankervillc Cat. p. 29. 



