316 PROCEEDINGS OF THE 



capable of being to a certain extent withdrawn into the folds of 

 the second segment. The feet are very short, squat, and knob- 

 like. The abdominal feet are scarcely developed, but 1 6 ma}^ be 

 easily counted, viz., 14 ventral and 2 anal. The colour is white, 

 assuming a greenish hue when the food-canal is filled. The head 

 is brown, darker at the sides, and around the mouth it is reddish- 

 brown, the eyes black, and the mandibles brown. On the back of 

 the second segment is a dark-brown plate, rounded at the ends, 

 and divided in the middle into two parts. On the same segment, 

 beneath, is a horse-shoe or dumb-bell shaped black plate, narrow 

 at the base, spreading out at both sides at the apex. On the next 

 two or three segments, also on the underside, there is on each, in 

 the centre, a round brown dot. At the last moult these markings 

 disappear; the head is then very pale brown, with darker 

 mandibles. 



The larvae are leaf-miners, like those of Fenella and Fhcenusa. 

 The female fly lays her eggs on the tip or sides of a leaf, and 

 whenever the larva escapes from the egg, it eats its way in between 

 the parenchyma, and devours a roundish irregular blotch between 

 the upper and lower epidermis, which becomes so transparent that 

 the creature inside can be easily seen by holding the leaf against 

 the light. There may be only one larva in a leaf, or there may 

 be three or four. In the latter case the several mines are in their 

 early stages distinct, but in course of time they become united into 

 one common blotch. The larvae are cleanly in tlieir habits, inso- 

 much as they open the sides of the leaf and expel the " frass " 

 tln^ough the opening made, while with Phcenusa the " frass " is 

 left in the blotch. Wlien they become full-fed they spin, attached 

 to the sides of the mine, a round, dark brown, flat cocoon,* where 

 they pass to pupae, and with the autumnal brood remain as 

 unclianged larvae over the winter until the spring. Most of the 

 species produce two broods in a year. 



Ohs. Besides those of the Pliyllotoma group, the only other leaf- 

 miner among the saw-flies is Dineum despeda, Klug. {cf. Kalten- 

 bach, Pflanzenfeinde, 9). It forms a blotch on the leaves of 

 Ranunculus repens, and from Kaltenbach's description, the larva 

 seems to resemble very closely, in habits and form, the larvae of 

 the group we have been discussing. It is a pity that Kaltenbacli 



* P/uenusa and Fcnclla pupate in the earth, not in the mines. 



