On Synthetic Types in Insects. 595 



resemblance of the female Panorpa to Tipula is very strik- 

 ing. In both the mouth parts are greatly elongated, and 

 the head much produced in that direction, leaving a very 

 short vertex ; and the antenntc are much the same in size 

 and shape. Panorpa is remarkable for the short, ovate, 

 compressed thorax, owing to the reduced size of the pro- 

 thorax, and the compactly massed notal and side pieces, 

 wherein it simulates Tipula ; but the resemblance is still 

 greater in the elongated episterna and coxae, and the long 

 slender legs. If we go more carefully into a comparison of 

 the notum of both insects, we shall find the large meso-scu- 

 tum, the short scutellum, and the longer than broad horse- 

 shoe-shaped scutum of the meta-thorax of Panorpa closely 

 resembling those pieces in Tipula. There is the same 

 form of the first pair of wings. In both the straight costa 

 bends gradually around at the apex, as the inner edge curves 

 up just as rapidly to meet the costa at the apex which is 

 situated in the middle line of the wing. Also in the dis- 

 position of the main nervures, their relative distances 

 apart, and their termination, even to the formation of the 

 pterostigma and the branches that lead to and from it, 

 the analogy is still maintained. At the base of the wing, 

 and towards the outer margin of Tipula there are a few 

 cross recurrent nervules, and irregularities in the branch- 

 ing of the principal nervures that remind us of the system 

 of net-veins that cross the wings of Panorpa. The 

 abdomen in the two genera is dilated at its base and ap- 

 pressed to the thorax ; and in its long, cylindrical form it 

 bears a similar proportion to the head and thorax, while 

 the swelled extremity and genital pieces in the females of 

 both genera are strictly analogous. Both genera agree, 

 according to the representations of authors, in supporting 

 themselves on their long legs, while introducing their slen- 

 der and i)ointed abdomen into the earth, when about to 

 deposit their eggs. 



