9834 Insects. 



back is a dark line caused by the dorsal vessel being seen through the 

 skin. Along the sides of the body on each segment are two projecting 

 elevations, of which the anterior is the larger ; both have a few long 

 white hairs (fig. 2). There are altogether twenty legs, the anterior 

 being glassy green, and, as shown in fig. 4, consisting of five joints. 

 The first joint is round and thick and proceeds in a vertical direction, 

 the rest are more or less horizontal ; on the under side of the second 

 are four setae ; the third has a thick fleshy knob in the same situa- 

 tion ; the fourth is cylindrical; the fifth consists of a little knob having 

 a pretty large horny claw of a brown colour. On the superior surface 

 of the leg are five setae. The abdomen is furnished with six pairs of 

 green membraneous legs, and there are two anal legs on the last 

 segment. Above the anus is often, but not invariably, found a brown 

 spot. The varieties of the larva are of a reddish or grayish colour, 

 with darker heads. 



As before stated, they spin up in cracks or crevices of the stem : the 

 cocoons are double, the outer case being of a loose texture, greenish or 

 yellow, and having something of the appearance of dried sputa, the 

 interior one being thicker and of a pale reddish colour (figs. 5 and 5 a). 

 The larvae remain concealed in these habitations through the whole 

 winter, and, disengaging themselves of the thin outer skin, change in 

 spring into little shining glassy pupae, from which the imagos appear 

 in the beginning of May, or sometimes as early as April, and may be 

 seen, during sunshine, flying about the stems of the elm-trees. From 

 this we may conclude the larva in question feeds on the leaves of the 

 elm : I do not know whether there is more than one brood in the 

 year. 



Both sexes of the imago are black ; the thorax sparsely covered with 

 short gray hairs ; palpi pale red ; legs reddish, having, however, all the 

 coxae, the apophyses, and the bases of the four anterior femora black; 

 the last two joints of the tarsi are blackish. In the male the wings are 

 also blackish, paler in the female, with the costa and stigma gray. 

 The length of the male is 6 millimetres, and of the female 7 milli- 

 metres. A further distinction between the sexes is found in the 

 structure of the antennae, those of the female being simply setaceous 

 and barely perceptibly hirsute (fig. 7); in the male the third joint is 

 prolonged underneath into a hairy protuberance, and the succeeding 

 joints are furnished on the lower and inner sides with black projecting 

 hairs. 



The ovipositor (fig. 10) in this species is short and compressed, 

 thick, and curved like a pruning-knife ; the saw (fig. 9) is a little 



