14 Bulletin American Museum of Natural History. [Vol. XVI, 



or not with his own genera. In both works, but especially 

 in the ' Geographische Geschichte,' he employed, when using 

 technical nomenclature, the binomial method in due form, 

 and in each work named a number of species supposed by 

 him to be new, in a perfectly citable manner. 



The greater part of the second volume of the ' Geograph- 

 ische Geschichte ' is devoted to a ' Verzeichniss aller bekann- 

 ten Quadrupeden,' in which, following Pennant, he divided 

 the Quadrupeds into four ' orders ' (some of them with sub- 

 divisions), 44 genera, and 388 species (consecutively num- 

 bered from i to 388), with a large number of additional forms 

 entered as " Unbestimmtere Arten." His treatment is thus 

 taxonomically methodical. In the earlier work he followed 

 closely the arrangement of Linnaeus as given in the twelfth 

 edition of the 'Systema Naturae.' 



In his later work he singularly ignores the new names he 

 gave in his earlier work, adopting those of Erxleben instead 

 of his own, even where Erxleben's names are of the same date, 

 and in general following closely the nomenclature of Pallas 

 and Erxleben. 



While the 'Geographische Geschichte' has been cited by 

 many subsequent systematic writers, especially by J. B. 

 Fischer in his 'Synopsis Mammalium,' and the new names 

 adopted when having priority, the 'Zoologiae Geographies ' 

 has been as uniformly neglected, although careful scrutiny 

 shows that both are equally entitled to recognition. In the 

 'Zoologiae' rather more new names were given than in the 

 later work, but when not synonyms of earlier names they in 

 most cases conflict with names given by Erxleben in his ' Sys- 

 tema Regni Animalis,' with the result that Erxleben's names 

 have been adopted while Zimmermann's have been over- 

 looked. Fortunately for science, both authors often gave the 

 same name to the same species, so that the uncertainty relates 

 to the citation of the authority for the name rather than to 

 the name itself. The explanation of this coincidence in names 

 is generally obvious, the species having been based on the 

 same sources of information, which in most cases suggested the 

 names bestowed independently by the two authors. 



