1 66 NATURAL SCIENCE. may. 



Mylodon ; and the range of the two latter is consequently carried much 

 further back in the Tertiary period. 



The remaining portions of the work are mainly devoted to 

 criticisms of genera and species founded by writers in Europe, the 

 majority of which are regarded as invalid. 



It is, perhaps, too much to expect that Dr. Burmeister's caustic 

 criticisms will at once check the reckless multiplication of names 

 now going on in South America ; but it will at least have the effect 

 of drawing attention in Europe to the serious nature of the evil. 

 Palaeontologists in Argentina have a magnificent field before them, 

 but it is not too much to say that some of them have so involved the 

 subject in a wilderness of meaningless terms, that many European 

 workers are repelled from giving to the fossil mammals of Argentina 

 the attention they so undoubtedly merit. 



Referring to the manner in which extinct mammals are named 

 in the New World, we may direct attention to the following para- 

 graph from a paper by Professor Marsh in the April number of the 

 American Journal of Science, p. 351 : — 



" The oldest ancestor of the horse, as yet undiscovered, 

 undoubtedly had five toes on each foot, and probably was not 

 larger than a rabbit, perhaps much smaller. This hypothetical 

 predecessor of the horse can now be predicated with certainty 

 from what is known of the early hoofed mammals. It may be called 

 Hippops, and its remains will be found at the base of the Tertiary, 

 or more likely in the latest Cretaceous." 



We have known cases of the description of genera and species by 

 telegraph, and we have unfortunately had some experience of the 

 ordinary struggle for " priority " in nomenclature ; .but we have never 

 yet met with anything equal to this latest development. Who, we 

 should like to know, is to decide which of the numerous small five- 

 toed hoofed animals that will probably be discovered someday at the 

 base of the Tertiaries must bear the name of Hippops ? 



An important memoir on the Oligocene mammals of the so-called 

 Siderolites of Egerkingen, near Soleure, Switzerland, is contributed 

 by Professor L. Riitimeyer, of Basle, to the publications of the 

 Swiss Palaeontological Society.' It is largely owing to the previous 

 researches of the Professor that our knowledge of this interesting and 

 prolific fauna is due ; and the present memoir affords much additional 

 information. The illustrations are excellent, and ought to aid 

 materially in comparisons with specimens from other localities. 

 Several forms previously known only from the nearly contem- 



1 " Die Eociine Saugethier-velt von Egerkingen," Ahh. schweiz. palaont. Ges., 

 vol. xviii., pp. 1-153, pis. i-viii, (1892). 



