CHAP. III. THE SCOLYMIN^. 79 



much less distinct, and of the same thickness, without 

 the last being manifestly larger ; they are always situated 

 across that part of the pillar which forms the lowest 

 part of the aperture, and not, as in Scolymus, higher up 

 towards the middle; the situation of these plaits, in 

 short, removes the genus from Scolymus, while their 

 form and direction separate it from Fasciolaria. The 

 variation in the shape of the shells is precisely what 

 may be expected from this intermediate position. In 

 such as approximate to Fasciolaria, the canal is nearly 

 as long as the spire ; while in those which lead to Scoly- 

 mus, it is shorter : many of the species, again, put on 

 the aspect of the spindle-shells (Fusus), and hence have 

 been arranged among them'; while others have the exte- 

 rior aspect of Murex. They are all of a moderate or 

 small size; and may be known from the Muricidce by 

 the distinctness of their transverse plaits, the absence of 

 internal tubercular teeth on the inner lip, and their 

 longer channel : they are united to the next genus by 

 Scolymus (or Plicatella) capitellum, a shell which may 

 be placed in either group without any violation of na- 

 ture : its predominant characters, however, appear to 

 us to be those of the last, inasmuch as the three plates 

 are nearly of equal thickness ; whereas, in Scolymus, the 

 lower are generally much smaller than the upper, and 

 their situation is much higher. This last-named genus 

 is a very striking one, and, being now disencumbered of 

 Plicatella, admits of a much more precise definition than 

 we originally gave it*: the shells are short, excessively 

 heavy; the spire acute, and almost turbinate : the pillar 

 short; the canal straight, and longer than the spire; 

 while the whorls are rugged, and beset with blunt, 

 simply folliculated, or plaited spines. All the species 

 are from warm countries. 



(69.) There is strong evidence to believe that the 



natural situation of Cancellaria is immediately after 



that of Scolymus; for, although the two genera, in their 



typical characters, are very different, we once possessed 



* Elements of Conchology, p. 21. 



