156 Mr. E. MacLachlan's Monograph of 



black ; lahrum black ; ijalpi black, yellow at the sutures ; 

 ocelli prominent, equidistant ; antennce blackish, yellowish 

 at the base. 



Prothorax swollen behind, black, transversely rugose 

 and pubescent, the hinder edge narrowly yellowish ; free 

 anterior and posterior portion of the prosternum yellow. 

 Meso- and 7neta-thorax black, the sutures beneath nar- 

 rowly yellow. 



Abdomen black ; sides with yellow interrupted double 

 lines, forming elongated spots on each segment, each 

 spot towards the dorsal surface is expanded widely on 

 the posterior margin of each segment; between these 

 spots is usually a smaller indistinct one ; beneath, each 

 segment is broadly- margined posteriorly with bright 

 yellow. Penultimate segment in the J" narrow, above 

 excised in the middle posteriorly, the sides very oblique, 

 beneath ending in two large bulbous bases ; in the open 

 space formed by the distant ventral margins of this seg- 

 ment is inserted on each side a thick yellow piece, dila- 

 ting greatly before the apex, which is produced into an 

 incurved crotchet ; penis broad, pointed at the apex, 

 with an impressed line in the middle ; above the two 

 crotchets before-mentioned, are two much longer ones 

 also directed inwards (and usually concealed in dry 

 specimens, owing to the collapsing of the adjacent parts) ; 

 above, the abdomen terminates in a hood-shaped hairy 

 piece, concave beneath, strongly directed upwards, 

 triangular when seen from the sides, and with the mar- 

 gins turned inwards. In the 9 the last ventral segment 

 is broadly rounded, the sides very oblique (PI. VIII, 

 figs. 3 a-d) . 



Legs yellowish ; femora all blackish except at the 

 extreme apex ; tarsi somewhat fuscescent. 



Wings (PI. VIII. fig. 3) broad, obtusely rounded, with 

 a slight smoky tinge, and yellowish at the extreme base ; 

 pterostigma dark brown (sometimes with a small hyaline 

 mark at each end) , large, the inner edge concave, the 

 outer edge very oblique, with two transverse veinlets, 

 one of which is usually forked ; these veinlets vary 

 greatly (exceptionally there is only one which very rarely 

 is simple) , the stigma commences at about the middle of 

 the areole below it, and ends nearly at the same point 

 with it ; twelve to fifteen costal veinlets, whereof one is 

 often forked ; snhcosta, as a rule, ending so close to the 

 pterostigma as to be almost confluent with its inner 



