CHAP. rv. CHARACTERS OF THE GENERA. 103 



This is one of the most natural, and, at the same time, 

 interesting groups ; for no recent species has yet been 

 found. The upper and finer plaits upon the pillar, 

 so characteristic of Harpula, now disappear, and leave 

 only one or two, or perhaps three, of the larger ones 

 at the base : the number of these plaits, iti fact, varies 

 according to the proximity or the remoteness of the 

 species to Harpula. The general shape is fusiform, the 

 whorls being strongly coronated with spines, and often 

 marked with transverse elevated ribs. The fifth and 

 last genus is Scaphella, where the upper plaits of the 

 pillar are as large as, or even larger than, the lower ; the 

 outer lip, also, is thickened within, and the suture of 

 the whorls is covered by a glazing of enamel. All the 

 species yet discovered are smooth ; and from the high 

 polish with which many are covered, there is every rea- 

 son to believe the animal has a strong affinity to that of 

 Mnrginella: this, indeed, is so obvious in the shells them- 

 selves, that Lamarck, as we before observed, has placed 

 the Scaphella Zebra (^jig. ?• «) ii^ that group. The form- 

 ation of the spire in general is conic, obtuse, but hardly 

 papillary ; but in certain aberrant shells, as S. fusifor- 

 mis and papillaris, the apex becomes thickened, and 

 assumes all the characters of the true volutes, and thus 

 unite with the melons by means of V. magnifica. 



(93.) By these typical characters, it appears to us 

 that the natural and primary divisions of the La- 

 marckian volutes are regulated. In this, and all similar 

 investigations, we have found it necessary to discard all 

 theoretical notions as to what should be the primary 

 types. No ordinary degree of impartiality is necessary 

 for accomplishing this ; because every naturalist, more 

 or less, is prone to form certain preconceived notions as 

 to what he thinks should he the types of any particular 

 family ; and thus, prejudiced in favour of some hypo- 

 thesis, he sits down to his task, exactly in that frame of 

 mind the most un suited for the investigation of truth. 

 We candidly confess that many years ago, when this 



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