REMINGTON: THE "APTERYGOTA" 503 



of genera and species named by him is astonishing, in total much exceeding the 

 Entotrophi named by all other taxonomists combined. 



The other Entotrophi students of special note have been P. Wygodzinsky, 

 H. Womersley, G. H. Carpenter, J. E. Denis, 0. F. Cook, J. W. Folsom, B. 

 Conde, K. Verhoeff, C. Delamare-Deboutteville, and H. E. Ewing, all taxono- 

 mists. Womersley (1939) has subdivided the lapygidae into subfamilies. 



The faunas of every region of the world are known in part, perhaps least 

 in the East Indies, Asia, and Africa. The embryology has been presented by 

 H. Uzel, J. Philiptschenko, and 0. W. Tiegs. Other morphologists of importance 

 are R. von Stummer-Traunfels, V. Willem, K. Verhoeff, R. E. Snodgrass, and 

 especially B. Grassi. Only fragments are known of the physiology and natural 

 history, other than some noteworthy papers by W. Marten and 0. Kosaroff and 

 occasional notes in primarily taxonomic papers. The only recent summary of 

 knowledge is that of Denis in the Traite de Zoologie. 



The systematics of this order (or subclass) is in a chaotic state. Almost 

 everything concerning its biology remains to be discovered. The anatomy, par- 

 ticularly of the organ systems, is in urgent need of modern investigation. The 

 three so-called families seem to be so different in fundamental structure that 

 their wide separation may become necessary when much more is known of their 

 anatomy and embryonic development. 



Thysanura 



This class (or order) includes two very different suborders (or orders) 

 which have long been treated as two similar families, the Machilidae and Lepis- 

 matidae (Remington, 1954). The former include saltatorial, heavily scaled, 

 free-living, mainly terrestrial forms with large compound eyes. The latter in- 

 clude nonsaltatorial, scaled or scaleless, myrmecophilous, termitophilous, domes- 

 tic, or free-living forms, some of which are subterranean and lack eyes or ocelli. 



The Thysanura have been known well since long before Linnaeus. As with 

 the Entotrophi, the premier worker has been Professor Silvestri. However, 

 for the Lepismatidae and allies the most important publication is Das System 

 der Lepismatiden, by K. Escherich (1905). In spite of its age, this fine mono- 

 graph remains the basic reference, and most taxonomic research since then has 

 been largely an elaboration. For the IMachilidae and allies no such revision 

 exists, and each new specialist must try to organize the great number of Silves- 

 tri's papers and correlate them with other publications by G. H. Carpenter, Jan 

 Stach, K. Verhoeff, H.. AVomersley, and especially the very important work of 

 P. Wygodzinsky. Species are known from most parts of the world. Verhoeff 

 (1910) attempted to classify the machiloid Thysanura on the basis of a few 

 genera, with mixed results. General studies of autecology of certain Thysanura 

 by A. Argilas, V. AVillem, Eder Lindsay, M. J. Delany, and H. L. Sweetman make 

 this group biologically better known than the Entotrophi and Protura. The re- 

 cent research on the skeletal morphology and myology by J. Barlet is noteworthy. 



The interrelations of Thysanura with other animals are unusually interest- 

 ing. Carpentier (1940) discovered that the very primitive Strepsiptera, the 

 Mengeidae, parasitize Lepismatidae. Silvestri subsequently described this situa- 

 tion in great detail. While most Thysanura harbor gregarine Protozoa, few other 



