80 THE ENTOMOLOGIST. 



widened laterally on apex of first abdominal segment ; a larger tri- 

 angular mark on the sides in front of this, and a narrow line on the 

 apex of the first abdominal segment, yellow. Legs black, the knees 

 yellowish, the apical third of the femora, and the base of the tibiae more 

 broadly in front, rufous. Antenna with a hook, the apical joints 

 rufous. Wings fuscous violaceous, the tegulae dark red. $ . Length, 

 16 mm. 



Mexico. 



Abdominal petiole as long as the thorax, the narrowed base half 

 the length of the dilated apex, which is longish ovate ; the second seg- 

 ment with a narrowed neck half the length of the apex, which is cup- 

 shaped, becoming gradually roundly widened towards the apex, followed 

 by a reflexed pale horn-like part. Clypeus wider than long, strongly 

 punctured, the apex depressed, smooth, broadly rounded. Front and 

 vertex closely, rugosely punctured, the ocelli • . ■ ; the hinder separated 

 from each other by the same distance as they are from the eyes. 

 Thorax closely punctured, the metanotum almost smooth, densely 

 covered with grey pubescence ; the metapleurae bare, shining, smooth, 

 except the lower part, with stout striae. The third and fourth abdo- 

 minal segments are closely punctured, the others smooth ; the red on 

 the apical is tinged with yellow. 



Belongs to Saussure's Division Didymogastra, B. The an- 

 tennal hook is narrow, curved, fully four times longer than it is 

 thick. Mandibles widened at the base, without distinct teeth, 

 the apex smooth, shining, bluntly rounded. 



Zethus {Didymogastra) carinicollis, sp. nov. 

 Black ; the clypeus, mandibles broadly in front to near the apex, 

 under side of antennal scape, a small spot above each antenna, a 

 narrow interrupted line on post-scutellum, a spot on the sides of apex 

 of petiole, produced below backwards along the sides, a longish spot, 

 narrowed at the base, on the base of the thickened part of second 

 abdominal segment, and a narrow line, all round, on the apices of the 

 second and third abdominal segments, lemon-yellow. The outer side 

 of the four anterior femora at the apex, their tibiae entirely, and a line 

 on the basal half of the hind tibiae behind, and two longish, moder- 

 ately wide marks on the apical slope of metanotum — the marks widest 

 below — bright lemon-yellow. Apical three joints of antennae pale 

 ochraceous yellow, including the "hook," which is only slightly 

 curved, is broad at the base, and becomes gradually narrowed to a 

 sharp point. Wings hyaline, the stigma and nervures black. $ . 

 Total length, 10 mm. 



Mexico. 



Abdominal petiole as long as the thorax, the basal fourth narrowed, 

 the rest becoming gradually widened at the base, and not much 

 narrowed at the apex. The second segment has a narrow, cylindrical 

 petiole about two-thirds of the length of the rest of the segment, which 

 is cup-shaped, rounded at the base, transverse at the apex ; it is, as is 

 also the first, smooth, shining, except for a narrow punctured band on 

 the apex ; the other segments are strongly punctured at the apex. 



