Linngeus, in the twelfth edition of the ' Sy sterna 

 Naturge' (1767), placed Lejnsma and Podura at the 

 head of the Aptera, followed by Termes and Pediculus. 

 Lepisma he characterised as follows : — " Pedes YI 

 cursorii. Os palpis 2 setaceis et 2 capitatis. Cauda 

 setosa : setis extensis. Corpus squamis inibricatum." 



Of Podura he gave the following description : — 

 " Pedes VI cursorii, Oculi 2 compositi ex octonis. 

 Cauda bifurca, saltatrix, inflexa. Antennae setacege 

 elongatse." 



Of Lepisma he described three species, L. saccharina, 

 L. polypoda, and L. terrestris. Of Podura he was 

 acquainted with fourteen, namely, P. viridis, polypoda, 

 atra, plumhea, minuta, nivalis, vaga, arborea, villosa, 

 cincta, pusilla, aquatica, fimetaria, and ambulans. 



LiNN^us, ' Sys. Naturae,' ed. xii. 



Podura viiidis = Smyntburus viridis. 



» polypoda Papirius polypodus. 



„ atra Smyntburus fuscus. 



,, plumbea Tomocerus plumbeus. 



„ minuta ? 



„ nivalis Degeeria nivalis ? 



„ vaga Orcbesella cincta. 



„ arborea Isotoma arborea. 



,, villosa Orcbesella villosa. 



„ cincta ,, cincta. 



„ pusilla Lepidocyrtus pusillus. 



„ aquatica Podura aquatica. 



„ fimetaria Lipura fimetaria. 



„ ambulans Campodea staphylinus.P 



Fabricius, in his ' Systema Entomologige,'^ places 

 Lepisma and Podura among his Synistata, between 

 Oniscus and Ephemera. He describes five species of 

 Lepisma, and sixteen of Podura, the latter being the 



* ' Systema Entomologise,' 1775. 



