and Position of the Hymenoptera. '97 



pidae are rarely fissured, and when this occurs they somewhat 

 resemble those of Pterojphorus, the lowest Lepidoptera ; and in 

 but a single hymenopterous genus, Anthuphorabia, are the eyes 

 in the male sex replaced by simple ocelli, like those in Lepisma 

 and other degradational forms of the lower Insects. 



What we know of the geological range of Insects proves that 

 the Hymenoptera were among the last to appear upon the 

 earth's surface. The researches of Messrs. Hartt and Scudder 

 prove that the earliest known forms of insects found in the 

 Devonian rocks of New Brunswick were gigantic, embryonic, 

 and, in fine, degradational types of Neuropterous and Ortho- 

 pterous insects. The Coleoptera appear in the Mesozoic rocks, 

 where the lower Hymenoptera first appear in limited numbers, 

 including representatives of the Formicidse and lower families, 

 and with them the Lepidoptera and Diptera. 



We have throughout this article spoken of the Neuroptera as 

 a group equivalent to the Orthoptera or Hemiptera or any other 

 of the suborders of Insects. We believe thoroughly in the 

 Neuroptera as limited by the early entomologists. The Odonata 

 are the types of the suborder, and the Termitidae, Psocidse, 

 Phryganeidae, Perlidse, Hemerobiidse, Sialidse, Panorpidae, Libel- 

 lulidse (Odonata), Ephemeridse, and Thysanura are closely inter- 

 dependent groups, and circumscribed by the most trenchant 

 characters, which they possess in common, and which separate 

 them from the closely allied Orthoptera, into which, by modern 

 German authors especially, some of their families appear to us 

 to have been unwarrantably merged. 



The families of this suborder differ more among themselves 

 than those of other suborders, by reason of the lowness of their 

 type, presenting an unusual number of degradational forms, the 

 connecting links of which have become, we must believe, extinct. 

 The Neuroptera are moreover true synthetic types, combining, 

 as do all decephalized embryonic forms, the structure of several 

 equivalent groups, presenting features which remind us of cha- 

 racters more fully wrought out in higher and more compactly 

 finished groups of Insects. 



DESCRIPTIONS OF THE FIGURES. 



Fig. 1. Bombus fervidus. The first stage of the semipupa, concealed by 

 the larval skin. The semipupa head lies under the bead (a) and 

 and the prothoracie ring {b,. The basal ring of the abdomen (c), 

 or fourth ring from the bead, is unchanged in form. This figure 

 also will suffice to rejresent the larva, though a little more pro- 

 duced anteriorly than in its natural form. 



Fiy. 2. Bombus fervidus. The second stage of the semipupa. The larval 

 skin entirely sloughed off, the two pairs of wing-pads lying 

 parallel, and very equal in size, like the wiugs of Neuroptera, 



