GENUS CLADIUS. 25 



arranged in definite order, each ending in a longish 

 stiff hair. The head is also covered with long hairs. 

 Its clypeus is large and irregularly heart-shaped. The 

 mandibles stout and double toothed. The maxillae 

 have five-jointed, short, conical palpi, the inner is 

 closely armed with bristle-like teeth, the outer lobe 

 stumpy and crooked. The spinning vessels are placed 

 close to the labium, which has three- jointed, short 

 palpi. The legs are hairy, their claws are sharp, 

 horny, and crooked ; the penultimate joint at the apex 

 projects outwards and forward over the preceding into 

 an oval ball-like mass. 



The usual colour of the larvoe is green or some 

 modification of it, but one species is black and another 

 orange. They frequent the under surface of the leaves, 

 eating only the parenchyma at first, then irregular 

 holes in them. Poplar, Salix, birch, and especially 

 rosaceous plants are their principal food. 



The cocoon is thin, double, irregular in shape, and 

 almost transparent. It is spun in the earth, under 

 bark, or in stems. 



The fact of the second cubital cellule receiving only 

 one of the recurrent nervures instead of both, as in 

 Nematus and Croesus, renders its recognition from these 

 genera very easy. By many authors Trichiocampus and 

 Prioplwrus are regarded as distinct genera, but inas- 

 much as the females of these sections, and Cladius 

 proper, do not differ to any appreciable extent, I have 

 not separated them because the males show some 

 difference in the structure of the antennae, and I am 

 confirmed in this opinion by the larvae being quite 

 similar in form and in the mode of pupation in all the 

 divisions. 



Cladius is confined to the temperate regions of the 

 New and Old Worlds. There are two European species 

 of Cladius and one North American ; seven European 

 species of Trichiocampus, which seems to be confined to 

 Europe ; and four European and two North -American 

 species of Priophorus. 



