xv FOSSIL NEUROPTERA 343 



and Neuroptera. Gerstaecker subsequently made use of a system 

 somewhat different from that of Erichson, uniting the Perlidae, 

 Ephemeridae, and Odonata into a group called Orthoptera 

 amphibiotica, from which the Termitidae and Psocidae were 

 excluded. The divisions we have here adopted differ but little 

 from those of Gerstaecker, though we have arranged them in a 

 very different manner. It is probable that not one-tenth part of 

 the Neuroptera existing in the world have yet been examined by 

 entomologists, and of those that are extant in collections, the 

 life-histories and development are very imperfectly known. "We 

 have, therefore, not considered it wise to adopt a system that 

 would involve great changes of nomenclature, while there can 

 be little hope of its permanency. 



Fossils. When considering the subject of fossil Insects we 

 briefly alluded to the discussions that have occurred as to whether 

 the fossils of the palaeozoic period should be referred to existing 

 Orders. Since the pages we allude to were printed, M. Brong- 

 niart's very important work 1 on the Insects of that epoch has 

 appeared. He considers that these ancient fossils may be classi- 

 fied with the existing Orders of Insects, though they cannot be 

 placed in existing families ; and he assigns the palaeozoic fossil 

 Insects at present known, to the Orders Neuroptera and Orthop- 

 tera, and to the homopterous division of Hemiptera. The greater 

 part of the species he looks on as Neuroptera, and places in 

 six families Megasecopterides, Protephemerides, Platypterides, 

 Stenodictyopterides, Protodonates, and Protoperlides. Of these 

 he considers the ancient Protephemerides, Protodonates, and 

 Protoperlides as the precursors, which, we presume, we may inter- 

 pret as the actual ancestors, of our existing Ephemeridae, Odonata, 

 and Perlidae. 



Some of the fossils restored and described by the French ento- 

 mologist are of great interest. ' We shall notice the Prote- 

 phemerides, Protodonates, and Protoperlides in connexion with 

 the families to which they are specially allied, and shall now 

 only allude to the quite extinct families of Neuroptera, the 

 Megasecopterides, Platypterides, and Stenodictyopterides. 



It is a peculiarity of these ancient Insects that they were 

 much larger creatures than the corresponding forms that now 

 exist. This may be due, to some extent, to the fact that tiny, 

 1 Insectcs fossiles des temps primaires, 1893, vol. i. and atlas. 



