INTKODUCTION. 5 



It was, probably, a young Isotoma. On the contrary, 

 tlie P. fimetaria of the 'Sys. Nat.' is described simply 

 as P. terrestris alba; but lie adds "non salit." It is 

 probable, therefore, that the P. fimetaria of the ' Sys. 

 Nat.,' though not that of the ' Faun. Suec.,' is the 

 species now known SiS LijnLr a fimetaria. The following 

 is a list of the species with the names used in the 

 present work : 



LiNN^TJS, ' Fauna Snecica.' 1746. 



Linn. 3Iihi. 



Podiira viiddis =: Smyntliurus vindis. 



atra Papirius polypodiis ? 



globosa fiisca nitida „ luscus, 



teres pkimbea Tomocerus plumbeiis ? 



nivalis „ nivalis, 



arborea nigra Isotoma arborea. 



aquatica nigra Podnra aquatica. 



viatica ,, viatica P 



teri'estris alba Toung Isotoma. 



In the second edition of the ' Fauna Suecica,' pub- 

 lished in 1761, Linnaeus omits the P. viatica, with 

 reference to which even in the first he had expressed 

 a doubt whether it was not identical with P. aquatica. 

 On the other hand, he adds two new species, P. cincta, 

 which is evidently Orchesella cincta ; and P. ambulans, 

 which is described as "P.a7nhulans alba, furcaextensa;" 

 while the somewhat longer description given in the 

 ' Syst. Nat.' is, " P. alba, cauda bifida extensa obtusa. 

 Corpus cylindricum, reliquis longius, album, moUe. 

 Punctum fuscum supra anum. Cauda setis 2 exten- 

 sis, longitudine ^ corporis. Non salit." This species 

 seems, from the above description, to have been a 

 Camjyodea. On the other hand, De Geer's P. ambulans 

 does not answer to either of the above descriptions, 

 but appears to be our Li^mra ambulans. It does not 

 seem to have been noticed by any writer that Lipura 

 ambulans is mentioned in the first edition of the ' Faun. 

 Suec.,' though not among the Fodurce, being described 

 as a Pediculus, although Linnaeus adds " facies omnino 

 Podviw." 



