HORN-TAILED SAW-FLIES. 311 



antennae are not feathered, and their joints vary in nuin})er from 

 nineteen to thirty-six. There are two marginal and four sub- 

 marginal cells, and the tibis of the second and third pairs of 

 legs have three spines. The name of the present species is 

 Lyda hortorum, and it is a really pretty insect. The liead 

 and thorax are black, and the abdomen a very warm orange 

 red. The wings are peculiarly shining. Mr. F. Smith tells 

 me that it is a very erratic and uncertain insect in its appear- 

 ance, being found in plenty one day, while on the next not a 

 solitary specimen is to be seen. It is exceedingly active and 

 difficult to catch, and while flvine:, its wino-s alitter in the 

 sunshine as if they were made of burnished gold. 



The larvae of this genus have no pro-legs on the abdomen, 

 but at the end of the body are two jointed projections some- 

 what resembling the true legs of the thorax. In consequence 

 of this structm-e, the movements of the larvae are slow and of a 

 gliding character. The larvae are semi-social, and live in 

 company after a very curious fashion. A number of them 

 associate together upon a branch, each larva spinning for 

 itself a separate case in which it lives, while the entire associa- 

 tion is covered by a common roof formed of the leaves of a tree 

 fastened to each other with silken webs. The larvae of some 

 species of Lyda form their cases of leaves, which they roll 

 up into a cylindrical form, and in which they live like the 

 caddis-worms in their tubes. 



We now come to a remarkable group of Saw-flies, which at 

 iirst sight scarcely seem to belong to the same family as those 

 which have just been mentioned. They are, indeed, so different 

 in aspect that many systematic entomologists have formed them 

 into a separate family, named Uroceridae, i.e. Horn-tailed Saw- 

 flies. In these insects, the saws are modified into a powerful 

 boring apparatus, by means of which the female insect can 

 drill a hole into solid timber, instead of merely cutting a groove 

 in soft bark. The body is nearly cylindrical in form, but flatter 

 in the males than in the females. The prothorax is elongated, 

 and forms a sort of neck between the head and the thorax. The 

 mandibles are strong and horny, though small ; and the front 

 tibiae have one spm- at the tij), and in the males the hinder 

 tibia*, are flattened. 



