Mr. J. D. Macdouald oti the Affinities of the Gasteropoda. 401 



The following Table exhibits a further subdivision of the first series, 

 according to the characters of their dental organs. 



^1 



. S a o s a.a 



OS o _es Pi g O r-i 







K CO g H Ph hJ h:! hJ ^ H P^ 



I. 



'^ S 

 S 2 



H!/2 



Ann. ^ M</^. A^ ///s/. Ser. 2. Vol. xix. 



26 



