442 HYMENOPTEKA. 



fourth joint a little longer than the fifth ; the other joints subequal, much thicker than 

 those preceding, scarcely becoming attenuated towards the apex. Head much excavated 

 behind, not margined ; closely and finely punctured all over, except above the mouth. 

 The upper and outer orbits of the eyes bear a few rather long fuscous hairs, and the 

 lower orbits on the inner side some closely pressed white ones. Thorax glabrous ; 

 pronotum emarginated in the middle in front, obscurely punctured. Basal region of 

 the mesothorax one half longer than broad, margined behind and at the sides, depressed 

 above in the middle, and clearly separated from the other part, obscurely punctured 

 and pallid testaceous in colour ; at its apex, on each side, is a blunt tooth ; the anterior 

 half of the mesothorax behind this part is transversely striated, the rest finely punctured 

 and obscurely, transversely striated. Metathorax flat, transversely striated ; its centre 

 truncated, becoming hollowed towards the apex. Abdomen a little shorter than the 

 thorax. Anterior coxae rather longer than the trochanters. 



The basal three joints of the antennae and the apical joint also are testaceous ; but in 

 one specimen the latter is black. The legs are sometimes entirely without black ; and 

 the abdomen in some examples is testaceous, and only black on the top. G. albo- 

 marginatus seems to vary considerably in colour and also in the intensity of the 

 punctuation of the upper surface. 



4. Gonatopus orbitalis. (Tab. XIX. fig. 3.) 



Niger, antennis (apice excepto), facie, orbitis oeulorum infra tarsisque rufo-testaceis. $ . 

 Long. 5 millim. 



Hah. Panama, Volcan de Chiriqui 3000 to 4000 feet {Champion). 



Antennas stout, and becoming gradually thickened towards the apex ; the basal joint 

 curved and not much thicker than the second ; the third joint shorter than the following 

 two, the fourth longer than the fifth ; the other joints become gradually shorter and 

 thicker to the penultimate, the latter being more than half the length of the preceding ; 

 the last five joints are black. The head is opaque, alutaceous, and sparsely covered 

 with long, white hair ; it is not much excavated either above or behind ; there is no 

 carina leading from the ocelli to the face. Thorax sparsely covered with rather long 

 white hairs ; prothorax smooth, shining. The narrow basal part of the mesothorax is 

 a little longer than broad, finely rugose, margined at the sides, and without tubercles, 

 the posterior portion is smooth and shining at the base, the remaining parts and the 

 mesopleurse being transversely striated. Metathorax transversely striated. Pro- and 

 mesostemum finely punctured ; the latter with a stout keel down the centre and 

 separated from the pleura by a wide and almost impunctate furrow. Abdomen sparsely 

 covered with long white hairs. Fore and hind coxae finely punctured, especially at 

 the sides ; the former about the same length as the trochanters. The anterior knees 

 and the base and apex of the trochanters are testaceous ; and the anterior femora and 

 tibiae are more or less piceous beneath. 



