NATURAL HISTORY SOCIETY OF GLASGOAV. 19 



truncated, and the superior edges produced into sharp spine-hke projec- 

 tions. In the male the joints and processes are densely covered with hairs; 

 in the female the antennae are only slightly hairy, Cerci long; posterior 

 calcaria a little shorter. Head densely covered with a fuscous pile — 

 Cladius 



1. Cladius difformis. 



Tenthredo difformis, Panz. F. G-. 62, 10. Lophyrus difformis, Spinola, 

 Ins. Lig. fasc. iii., T. 2. 153; Fallen Acta Holm. 1808, 41, 5-6; 

 Mon. Tenth. 18, 9. Cladius difformis. Leach, Zool. Mis. iii., 130; 

 Lepelletier, Mon. Tenth. bS, 165; Fauna Fr., pi. 12, f. 4; Brulle 

 An. Soc. Ent. Fr. i., 308, pi. xi. f. 10-12 (lar.); Dahlbom, Consp., 

 Tenth., 34; Prod. Hymen., 100, 35, pi. 2. f. 81-85; Hart., 

 Blatt. 11. IIolzw. 175, 1, Taf. ii. f. 20; Stephens, 111. Brit. 

 Ent., vii., 23, 1. Thomson, Hymen. Scand., i., 71, 1; v. Vollen- 

 hoven, Tidjr. Ent., iii., 202-205, pi. 9; Ent. No. 139, 26-29; 

 Kaltenbach, Pflanzenfeinde, 222; Brischke, Beschr. 10, Taf. ii. f. 3. 

 Cladius Geoff royi, Lep. Mon. Tenth. 58, 166. 



Black, shining, covered with scattered grey pubescence ; knees, 

 tibiae and tarsi yellowish white ; last two or three joints of tarsi 

 (especially the posterior) pale brown ; cerci long ; epistoma slightly 

 convex. Wings faintly smoky, apex clearer, nervures at base and 

 costa brownish white, or pale reddish ; nervures at apex blackish, 

 stigma obscure black. Tegulae grey or white. Length 4 to 5 

 lines. 



The male is easily known by the form of the antennae ; smaller 

 and thinner than the female. 



Beyond slight colour aberrations, I have not noted any varieties 

 of this species in Britain. Hartig mentions a very small form 

 with the sheaths of the saw and the last abdominal segment 

 milk-white — G. ladeus, sibi. C. Geoffroyi differs merely in having 

 the prolongation of the 3d antennal joint white, a peculiarity 

 probably owing — as van Vollenhoven has suggested — to want of 

 development. 



The larva lives on the underside of the leaves of various roses, 

 both cultivated and wild, in which it devours irregular holes ; at 

 first these are small, but by degrees they become larger, and 

 occasionally the edge of the leaf is eaten. The mid-rib is never 

 touched and the other nerves rarely, if ever. Two generations 

 occur in a year, the first in May and the early part of June, the 

 second in August and September. From the summer brood the 



