264 MKRISTIC VARIATION. [PART i. 



outside of tin- central plate a pair of almost wholly separate 

 denude-, nn one -ide r-f.nvspond with a large, imperfectly divided 

 denude fit' tin- i.thi-r -ide. A very similar specimen is figured by 

 KIM 1. 1. 1 Norake .Y"/v///-//W-,'./y,., vm. PI. v. fig. 16. 



The number found in one part of the radii la is usually main- 

 tained thruiighout the whole series, but this is not always so. 

 A case in \\liidi the number of centrals at the anterior end of 

 tin radula was G. and at the posterior end 8, is given by FKIELE, 

 Norske Sordini c.^-K'j>., 1882, vm. p. 27, Taf. v. fig. 17. 



