496 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



by entomologists was that of Westwood's Entomologist's Text-hook (1838), with 



the following arrangement: 



Insecta 



Class Crustacea 

 Class Arachnida 

 Class Ametabola 



Order Chilognatha (:=Dlplopoda) 

 Order Chilopoda 

 Order Thysanura 



Family Lepismidae 

 Family Poduridae 

 Order Anoplura 

 Class Ptilota (winged orders and fleas) 



By 1865 both Campodea and laijyx were known, and Meinert combined them 

 as the family Campodeae. He restricted the order Thysanura to that family and 

 the family Podurae. The family Lepismae (= modern Thysanura) he grouped 

 with the Orthoptera in another order under Fabricius' name, Ulonata. He recog- 

 nized the affinity between the lepismatids and the Orthoptera, a closeness not 

 shared with lapyx and Campodea. We are now returning to such a view, al- 

 though most of our reasons are not those of Meinert. 



Lubbock (1870) first set aside the order Collembola as distinct. He referred 

 to it as an "island" apart from the "continent" of true insects, including the 

 Thysanura {s. lat.). 



Packard was the earliest serious student of the American Collembola, Thy- 

 sanura, and allied myriapod groups, and his contributions to their taxonomy 

 and phylogeny are outstanding. He recognized the closeness of the remarkable 

 Symphyla to the Collembola and the Cinura (= modern Entotrophi and Thy- 

 sanura). Packard (1883) divided the insects into five superorders, four con- 

 taining the groups with wings or with winged ancestors and the last as follows : 



Superorder Synaptera 

 Order Thysanura 

 Suborder Cinura 

 Suborder Symphyla 

 Suborder Collembola 



In the Textbook (1898) Packard later made the Synaptera one of two sub- 

 classes. The other combined the first four of his former superorders under 

 Gegenbaur's (1878, p. 244) name Pterygota. 



The separation of the "Campodeae" from the "Lepismae" by Meinert was 

 generally ignored, but twenty-three years later Grassi (1888) presented a com- 

 prehensive monograph of the external and internal structures of these two 

 groups, showing conclusively their distinctness. He proposed for the first time 

 a higher category name for the Campodea and lapijx group. Like ^Meinert, 

 Grassi recognized the nearness of the Thysanura to the Orthoptera: 



Superorder Orthoptera 

 Order Thysanura 



Suborder Entotrophi 



Family Campodeadae 

 Family Japygidae 

 Suborder Ectotrophi 

 Family Machilidae 

 Family Lepismidae 



