520 Mr. E. W. Eaddow— Names of Fossils. 



of generic or subgeneric names of Ammonites, and the confusion 

 that appears to have arisen concerning what have hitherto been 

 regarded as recognizable species. 



It is indeed diflScult for the " general geologist " to understand 

 and remember the subgeneric names of Ammonites, especially when 

 the form known as Sarpoceras concavum has been recently changed 

 again to Lioceras concavum, and IT. Miirchisoyice has become Ludwigia 

 Murchisonce. One cannot help wondering what other changes may 

 be in store for us. It is, however, still more perplexing to be told 

 by one who has devoted especial attention to the subject, and who is 

 in every way qualified to speak with authority, that the form which 

 is " called by D'Orbigny, Wright, and others Am. serpentinus, and is 

 so labelled in museums and private collections, is the Ammonites 

 falcifer of Sowerby." (See S. S. Buckman, Geol. Mag. Sept. 1887, 

 p. 396.) "What is then to become of our " Ser-pentinus-heds" ^ 

 Again, the same palaeontologist tells us that the occurrence of 

 Ammonites Jurensis in England is doubtful, in fact he has never yet 

 ascertained its presence in our strata. (Proc. Cotteswold Club, 

 vol. ix. part 2, 1887.) What then is to become of our '' Jurensis- 

 beds " ? Once more, the recognition of the true Ammonites Sowerbyi 

 appears to be a source of great difficulty to judge by the remarks 

 made in a recent volume of the Paleeontographical Society. 

 (Hudleston, Introduction to Gasteropoda of the Inferior Oolite.) 

 Even the " Soioerbyi-heds " are in trouble ! 



The question that perhaps naturally arises to an outsider is this, 

 cannot these well-known specific names be applied in a sufficiently 

 comprehensive way to include the forms which the older authorities 

 recognized under the names of A. serpentinus, A. Jurensis, and A. 

 Sowerbyi, respectively ? 



To go further, would not the adoption of the trinomial system 

 meet all requirements, and be the means not only of doing justice to 

 the more minute and exceedingly important observations made now- 

 a-days, but also of placing the results of this detailed work in a 

 manner more intelligible to the " general geologist " ? It would 

 seem likely imder present circumstances that some collective group- 

 ing of the many species now made must eventually take place, if 

 any individuals except the specialists in each department are to 

 follow the progress of palaeontology, or attempt the naming of their 

 fossils : and this grouping might be done under the trinomial system, 

 better, it appears to me, than under the system which introduces 

 subgeneric names. So far as the geologist is concerned, he simply 

 requires a definition of specific characters, and a key to the distribu- 

 tion of each species in time and space. Where particular varieties 

 are confined to special horizons, he can obtain this precise information 

 on the trinomial system. Moreover, the adoption of that system 

 would fulfil all the requirements of the biologist. No doubt many 

 more specimens are available now for study than was formerly the 

 case, and it becomes more and more difficult to draw rigid lines ; 

 but there seems to be a tendency to confine specific characters within 

 narrower limits than heretofore, and this perhaps is the real source 



