THE TENTHREDINIDM. 1 6/ 



distinguishable on account of the movable, dentate, savv-hke 

 ovipositor which is attached to the abdomen of the females. 



This is a wonderful little instrument. It is in the form of 

 a double saw, the length of which varies according to the species, 

 and there are from fifteen to twenty or more regularly placed teeth 

 added to the cutting edge. But the little saw of the TentJiredo is 

 not always so simple in its construction as that of a carpenter, 

 for the teeth or dentations are covered with others, so that 

 the teeth of the saw are themselves toothed. The perfection 

 of this minute weapon suggests that manufacturers might take 

 a lesson from it and invent a cutting saw with double serrations, 

 which might be of infinite use in the arts. 



The double saw corresponds to the stylets of the sting of the 

 wasp and bee. The two valves are kept fixed by being inserted 

 or fixed into a scale which adheres to the sides of the abdomen ; 

 and the process that surrounds the stylets of the sting may be 

 noticed in its rudimentary condition as a thin membrane in the 

 saw-flies, but it is of no importance to them. 



The Tcnthrcdinidcs have active dispositions, and are orna- 

 mented with various colours, and their bodies are smooth and 

 shining. They do not consume much nourishment in the adult 

 stage, and they then appear to prefer fruit, which they snip in 

 pieces with the aid of their cutting mandibles. 



The larvae resemble caterpillars in their shape and habits, yet 

 it is hardly possible for any one to mistake them for the miniature 

 form of the Lcpidoptera. It is true that amateur entomologists 

 have nourished and taken vast pains with the larvae, believing 

 that they would eventually turn to new and splendid butterflies, 

 and that they have been surprised at the evolution of a saw-fly 

 instead of the expected scale-winged insect. But in spite of 

 the resemblance, the mistake ought never to occur if a careful 

 examination be made. 



Caterpillars have never more than five pairs of membranous 

 or hind legs, but the larvae of the saw-flies have generally seven 

 or eight, and never less than six pairs. The feet have, however, 

 circles of hooks, like the caterpillars. The head is always rounder 

 and more globular, and the eyes are more wide apart and distinct, 

 than in the larva; of the butterflies. The saw-fly lai-va: have, 



