THE INSECTS. 315 



American writers have attempted to overcome this diffi- 

 culty by considering it a collection of ' synthetic types.' 

 In adopting metamorphosis as a basis of classification, 

 we prefer to take another course, and to follow Erich- 

 son, who (in 1839) boldly transferred all those Neuroptera 

 with incomplete metamorphoses to the Orthoptera as a 

 sub-order, although, in dealing with the Neuroptera in the 

 light of a specialist, division into several orders appears the 

 more natural course." 



The orders, according to this author, with the metamor- 

 phosis complete are Hymenoptera (bees, &c.) ; Diptera 

 (flies, gnats, &c.) ; Lepidoptera (butterflies, moths, &c.) ; 

 Neuroptera, divided into two sub-orders Trichoptera (sedge- 

 flies, &c.) and Planipennia (saw-flies, &c.). 



With the metamorphosis incomplete are placed the order 

 Orthoptera, divided into two sub-orders Pseudo- Neuroptera 

 (the Ephemeridce, &c.) and Genuina and the order Hemip- 

 tera, divided into two sub-orders Heteroptera and Hemip- 

 tera (grasshoppers, &c.). 



We propose in describing these to alter the classification 

 in which they are thus placed, and to take them, as better 

 suited for our purpose, in the following order: 



I, The Neuroptera, with its two sub-orders, Trichoptera 

 and Planipennia; 2, the Orthoptera, with its sub-order 

 Pseudo-Neuroptera ; 3, the Hemiptera ; 4, Hymenoptera; 

 5, Diptera ; and lastly, the Lepidoptera. 



The Neuroptera (with metamorphosis complete) are de- 

 scribed as having four membranous wings, for the most 

 part densely reticulate, more or less clothed with hairs, but 

 without true scales ; very frequently the hairs are on the 

 neuration only ; mouth mandibulate. Pupa has its mem- 

 bers free. This order is divided into two subdivisions 

 Trichoptera and Planipennia. 



The Trichoptera (hairy-winged] or Caddis-Flies " form a 

 very natural and sharply defined group, distinguished by 

 their rudimentary mouth parts, with the exception of two 

 pairs of palpi, 1 which are strongly developed, the maxillary 



1 The palpus is a slender appendage, somewhat similar in structure 

 to the antennae, only shorter, and composed of fewer joints, varying 



