10 FIFTH ANNUAL REPORT 



worms which gnaw and destroy. The whole section is well charac- 

 terized by the uniformly maggot-like, legless nature of the larva. 

 The transformations are complete, but the chitinous larval covering 

 is often so very thin and delicate that the budding of the members, 

 or gradual growth of the pupa underneath, is quite plainly visible, 

 and the skin often peels off in delicate flakes, so that the transition from 

 larva to pupa is not so marked and sudden as in those insects which 

 have thicker skins. 



The terebrantine Hymenoptera, or Piercers, are again divisible 

 into two subsections : 1st, the Entomophaga, which are likewise, with 

 the exception of a few gall-markers, beneficial to man; 2d, the Phy- 

 TOPHAGA, comprising the Horn-tails C UroGeridce)^ and the Saw-flies 

 {TentliredinidcE)^ all of which are vegetable feeders in the larva state, 

 those of the first family boring into the trees, and those of the second 

 either feeding externally on leaves, or inclosed in galls. They are at 

 once distinguished from the other Hymenoptera by the larvas having 

 true legs, which, however, in the case of the Horn-tails, are very small 

 and exarticulate. The larvae of many Saw-flies have, besides, prolegs, 

 which are, however, always distinguishable from those of Lepidopte- 

 rous larvas by being more numerous and by having no hooks. 



[i^ig- 3-] 2 — OoLEOPTERA (J\i>Xtuz^ a slieatli ; -r^pa^ wings), 



Beetles or Shield-winged Insects. Characterized 

 by having four wings, the front pair (called ely- 

 tra) horny or leathery, and usually united down 

 the back with a straight suture when at rest, the 

 hind ones membranous and folded up under the 

 elytra when at rest (Fig. 3). Transformations 

 complete. 



This is an Order of great importance, and in 

 the vast number and diversity of the species 

 coTALPA L.vNiGEUA. compHsed in it outranks any of the others. The 

 ease with which the insects of this Order are obtained and preserved 

 makes it one of the most attractive to the amateur, and beetles are, 

 perhaps, of all insects, the best known and understood in the popular 

 mind. For the same reason they have, in the perfect state, received 

 most attention from entomologists ; but their transformations and 

 preparatory forms yet offer a wide and inviting field for the student. 

 The simplest and best-known classification of the beetles is the tarsal 

 system, founded on the number of joints to the tarsi, by which we get 

 four great sections : 1, Pentamera, in which all the tarsi are 5-jointed ; 

 2, Heteromera, with the four anterior 5-jointed and the two posterior 

 4-jointed; 3, Pseudo-tetramera, with apparently only 4 joints to all 

 the tarsi, though, in reality, there is a fifth penultimate joint, diminu- 

 tive and concealed ; 4, Pseudo-trimera, with apparently only 3 joints 

 to all the tarsi. This system, like most others, is not perfect, as 



