11 PREFACE. 



make the work suitable for the use of Natural History Classes in 

 the Universities.* 



To facilitate reference, and meet the most general requii-e- 

 ments, the number of large groups and genera of shells has been 

 restricted as much as possible, and those less important or less 

 understood, have been treated as " sub-genera." A great many 

 duplicate and unnecessary names have been mentioned only, as 

 will be seen by a glance at the Index, where they are printed in 

 italics; the writer's own wishes coincide with those of the dis- 

 tinguished botanist Sir J. E. Smith, that " the system should 

 not be encumbered with such names;" but they have been 

 admitted in deference to custom, and general opinion. It has 

 even been suggested that an additional list of synonymes might 

 be given at the end, and some progress was made in preparing 

 one ; but it was found that it would occupy the whole of the 

 " Third Part," and consisted of names chiefly obsolete, or "based 

 on misconception of characters, and of the purpose of generic 

 appellations.''' (Forbes and Hanley, IV. 265.)t 



The rules of the British Association, intended to secm*e uni- 

 formity, have called into existence a few active opponents, 

 seeking to distinguish themselves by the employment of pre- 

 Linnean, and MS. names, on the pretence of carrying out the 

 " law of priority," (p. 60.) But this folly has reached its height 

 and will faU into contempt when it has lost its novelty. J 



* The former parts have been already adopted as a text book at Edinburgh, 

 in the largest natural history class in the kingdom, under Prof. E. Forbes ; 

 and also by Profs. King and Melville, of Q,ueen's College, Galway ; Prof. 

 Tennant, of King's, and Prof. Morris, of University Coll., London ; and Prof. 

 Sedgvvick at Cambridge. 



t All the blundering and bad spelling of English and Prench genus- 

 makers will be found carefully recorded in the " Index Generum Malaco- 

 zoorum," by the accurate and lamented Dr. IIerrmannsen, — a work 

 indispensable to every writer on Conchology. 



it One example will suffice. In an " Athena?um " report, by Prof. E. 

 Forbes, the name " Lottia fulva" was misprinted "Jothia fulva:" but 

 althougli immediately corrected, the erraium was formally installed as a " new 

 genus," in the works of Gray, Philippi, Catlow, Adams, and other conchologists ! 



