28 INTRODUCTION. 



This species, however, differs greatly from the generic 

 description given by Franenfeld, particularly in the 

 appendages of the head, the true nature of which I 

 cannot understand. 



In 1854 M. H. L. Elditt^ published an " Einleitung 

 zur Monographic der Thysanuren,' being an analysis 

 of the memoirs by Nicolet and Bourlet. 



In the following year M. Brauer" mentions the 

 presence on snow of a Podura which he refers to the 

 Isotoma saltans of Agassiz. 



I have been unable to see M. Papon's note, " IJeber 

 eineim Februar, 1855, bei Chur beobachtete Desoria.'"^ 



In 1858 M. J. A. Herklots* proposed the name of 

 Degeeria ])i for the Podura arhorea grisea of De Geer, 

 which, he observes, is quite distinct from the D. ni- 

 valis. His observations on the subject seem to me 

 perfectly correct, but both his name and also that of 

 P. nigromaculata, proposed for the same species by 

 Templeton, must give way to the far earlier one of 

 D. annulata. 



In the same year M. Low^ published a note on a 

 Podura found in considerable numbers on the surface 

 of snow. He refers it to the Achorutes murorum of 

 Gervais, which I consider to be identical with the 

 A. dubius of Templeton. He observes that out of 104 

 European Podiiridce, 24 have been observed on the 

 surface of snow. 



M. Kolenati^ gave, also in 1858, an abstract of 

 Nicolet' s classification of the group, and a list of the 

 species. 



In this country the study of the Oollembola has been 

 singularly neglected. In fact Mr. Templeton's was the 

 only memoir on the British species which had appeared 



' ' Entomologisclie Zeitimg,' 1854. 



- ' VerhandluBgen des Zoolog. Botanis. Yereins. Wien,' 1855. 

 3 ^ ' Jalir. d. Nat. Ges. Graubundens,' 1856. 



^ ' Memoires d'Entomologie de la Societe Entomologique des Paj's 

 Bas' for 1858. 



■' ' Verb, der k. k. Zoob Bot. Gesellscbaft ' of Vienna, 1858. 



« ' Wien. Entomob Monat..' Bd. 2, No. 5. 



