X PREFACE. 



while another, perhaps published one or two years previously, had the misfortune 

 never to become known, it would be unwise to cancel the well known name and 

 to replace it by another. It is to be regretted that Klein's labours were so little 

 acknowledged by our old veterans in conchology, as, for instance, by Lamarck, 

 who clearly used Klein a great deal, but subjected almost everything to some 

 change or other. If Lamarck had worked out conchology, as regards generic 

 groups, in the spirit indicated by Klein, he would have advanced our science by at 

 least 30 years. However, I will not now dwell upon this subject ; the facts are 

 well known. The system of disregarding the generic names given prior to 1758 

 is not adhered to even by the otherwise strictest devotees of the rule. I may 

 among many celebrated authors only quote Deshayes, who admits Adanson's 

 genera Fedipes and Nerita, although they bear the date 1757; and surely no 

 sensible man would object to the propriety of this. Others accept still older names 

 unconsciously, but agitate equally ignorantly in favor of the rule. 



Another not less important point to which I would briefly allude is, the case 

 relating to a generic name having been proposed to include several varied species^ 

 where the type of the genus had not been particularly pointed out. The rules on 

 this question have been also partially established by Linne (in Phil. Bot.) and were 

 emended by the British Association Committee. It is, however, surprising to meet 

 with the inconsequences in reasoning which occur in carrying out the provisions 

 of this rule, particularly in fossil conchology. 



Let us take an example : In the second edition of his Paris basin fossils, 

 Deshayes argues, in accordance with the above quoted rule, in favor of the pro- 

 priety of retaining the generic names Capsa of Bruguier, Fsammobia and Sangui- 

 nolaria of Lamarck, JDonax of Linne, and many others, under which species had 

 been described which no conchologist would at the present time dream of placing 

 in one and the same genus. Mr. Deshayes himself is, however, not consistent in 

 his argument. 



Schuhmacher proposed in 1817 a new genus, Gastrana, referring to it two 

 species formerly known as Tellina AUldgardiana and Venus monstrosa. Shortly 

 after it was discovered that the latter species belonged to the genus Tetricola, sug- 

 gested by Lamarck already in 1801, but the distinction of the first from Tellina 

 was confirmed. What reason then can there exist for not applying to it the name 

 Gastrana instead of replacing it by that of Fragilia which is of latter date ? 

 Mr. Deshayes solves the question. He tells us that it devolves upon the author 

 himself to decide which is the type of the genus, though really in this case only one 



