18 PROCEEDINGS OF THE 



Larva twenty-footed, the 5th and 12th segments footless, 

 cylindrical, with roundish head ; the skin beset all over with 

 tubercles, which are usually arranged in a definite order, each 

 ending in a long sharp-pointed hair. The head is distinctly 

 separated from the body, roundish, always covered with short stiff 

 hairs. The clypeus large and, usually, irregularly heart-shaped. 

 The mandibles are strongly developed, of a horny consistence, and 

 double-toothed at the point. The maxillae have 5-jointed conical 

 palpi. The inner lobe of the maxilla has on its side seven to 

 twelve bristle-like teeth, the whole having the appearance of a 

 brush, the two at the apex being separated by a space from the 

 others ; the outer lobe is stumpy and crooked. The spinning 

 vessels are situated close to the labium, which is provided with 

 3-jointed palpi. The feet are slightly haired ; the claws are sharp, 

 horny, and crooked ; the second last joint, at its apex, projects 

 outwards and forwards over the preceding joint into an oval ball- 

 like mass. The claspers do not differ from those of the other 

 genera. 



The usual colour of the larvae is green, or some modification of 

 it, and without markings, except in the case of one species which 

 has the body orange, with black dots. They always frequent the 

 under surface of the leaves of the food-plants (usually species of 

 Eosaceae: with one species, poplar, and with another, Salix pentan- 

 dra). They eat out the parenchyma at first, and then proceed to 

 make holes in the leaves. 



The larvae are attacked parasitically by various species of 

 Iclmeumonidae, and I have also found Gordiidae in them. 



The pupa offers no striking peculiarity. The cocoon is thin, 

 double, irregular, and almost transparent, and is spun in the earth. 



So far as is known, the species of this genus are confined to 

 temperate climates. 



A. In the male the two basal joints are short and thick, the 2u being a 

 little smaller than the first; on the underside of the 3d, at the base, there 

 is a small knob-like projection; at the apex, on the upper side of the same 

 joint, there is a branch-like prolongation, nearly as long as the segment 

 itself; on the 4th, 5th, and 6th joints there are similar processes, each 

 gradually decreasing in length ; the 7th is a little pointed upwards at the 

 apex; the terminal joint is almost awl-shaped. In the female the basal 

 joint is nearly globose, and about double the size of the 2d, which is very 

 small; the following joints become gradually shorter and thinner; the 3d 

 is arched beneath ; it and the 4th, 5th, and 6th have their apices obliquely 



