292 Mr. R. McLachlan on 



The middle of the dorsal margin of the last abdominal 

 segment is intensely black and scabrous, slightly rolled 

 inwards ; beneath this margin are seen the black and 

 blunt tips of the short cq^p. intern bed : app. sup. small, 

 spoon-shaped, yellow, fringed ; app. inf. large, yellow, 

 formed of two broad and thin plates, the inferior edge 

 of which is excised, this edge showing a thickened 

 geniculate portion which is continued beyond the 

 plates in the form of a thin up-directed spine (too 

 short and thick in Brauer's figure) which is flattened, and 

 intensely black and shining at the tip, the thickened 

 margin is strongly fringed internally ; penis sheaths 

 broad, curved upwards and inwards, appearing to be 

 soldered together. 



Genus Halesus. 



In a paper on Monocentra lepidoptera of Rambur, 

 which will be published in the Ann. Soc. Ent. de Fi-ance, 

 I have, in pointing out the affinity of that insect to the 

 genus Halesus, proposed to divide the latter into three, 

 viz. : — 1. Halesus proper, including those species in 

 which the ^ has no pouch in the hind- wing ; 2. Drusus, 

 a name proposed by Stephens in his " Catalogue of 

 British Insects,'^ but afterwards erroneously reduced by 

 him to a section of Anaholia (" Illustrations,^' Mandib. 

 vol. vi.), including the species with a short pou.ch, and 

 with hairy clothing; and 3. Jlfonocen^ra, distinguished by 

 scale-like clothing, and a long pouch in the hind-wing. 

 All have 1, 3, 3 spurs in both sexes. 



The species which should be referred to Drusus are 

 very numerous, especially in mountainous countries, but 

 are mostly undescribed. A few descriptions follow here, 

 and, pending the appearance of the above-noted paper, 

 they are referred to Halesus in the broad sense. Fcltos- 

 tomis of Kolenati can only be distinguished from Drusus 

 by the spurless anterior tibia3 of the male. 



Halesus (Drusus) Muelleei, n. sp. (PI. XIV. fig. 3). 



Black. Antennce blackish fuscous, not annulate. 

 Head with strong golden-yellow hairs on the face and 

 between the antennfe : palpi fuscous : occiput slightly 

 swollen, with a median impressed longitudinal line ; two 



