14 PROCEEDINGS OF THE 



The male has the antennae longer, otherwise it does not differ 

 from the female. 



This is the largest of the European species. It is easily- 

 recognised by the colour of the feet and wings, alar cell-structure, 

 and deep frontal sutures. 



A common species, occurring from the London district to 

 Strath Glass in Inverness-shire. 



Larva white ; the head pale-brown, darker at the sides ; mouth 

 reddish-brown ; eyespots black. The 2d segment above bears a 

 shield-like black plate ; beneath there is a large black plate on 

 the same segment, and on each of the 3d, 4th, 5th, and 6th, a 

 smaller dot ; along the sides are arranged a number of black dots, 

 a large one on the 2d, three on the 3d, and four on the others, the 

 latter being smaller than those in front. The thoracic feet are 

 banded with black ; the abdominal ones have, above, a small black 

 band ; and the anal pair are broadly marked with the same colour. 

 The penultimate segment sometimes bears in the centre two small 

 black dots. The number of dots varies a good deal ; they are often 

 absent from the 5th, 6th, and penultimate, and along the sides 

 some individuals have more and others less than usual. When 

 full fed the markings are cast off. Length 9 to 11 lines. 



The pupa is yellowish-white. 



The larvae live gregariously — often to the number of seven or 

 eight in a single leaf —in the leaves of the birch, appearing in 

 May and June, and again in the autumn. Brischke {I.e., 71) 

 mentions as parasites of this species, Perilissus macrojjijgus, Holmgr., 

 P. soleatus, Holmgr., and P. verticalis, Brischke. 



These are all the species that I can record with certainty as 

 British. Leach formed his genus Messa on an insect which he 

 referred to hortulana, Klug. He, however, stated that it had one 

 marginal and four sub-marginal cellules, while Hartig says that 

 the true hortulana is a true Fhaenusa. I suspect, then, that Messa 

 was formed on some small species of Nematus. Stephens also 

 describes (111. Brit. Ent., vii., 40) Messa hortulana, but Mr F. 

 Smith has examined for me his types; and, from the account 

 which Mr Smith sends, it is clear that Stephens' hortulana is 

 neither a Messa nor a Fhaenusa, it having two marginal and four 

 sub-marginal cellules : it is probably a Blennoeamjm. In the 

 meantime, therefore, hortulana must be deleted from our lists ; 



