46 HYMENOPTEKA. 



depressed. Thorax shining, punctured, but not strongly ; the edges of the sutures and 

 the sides of the middle segment densely fringed with silvery pubescence ; the other 

 parts with a short pale cinereous pubescence. There is a short broad suture on either 

 side of the mesonotum at the tegulae; the pleural suture is oblique and broad; the 

 middle segment has a wide and deep V-shaped depression in the centre. Abdomen 

 shining, covered with a short cinereous pile, especially at the apices of the segments ; 

 petiole thickened and tumid towards the apex, on the top at the apex considerably 

 higher than the first segment ; first segment petioliform, becoming gradually thickened 

 towards the apex ; the second segment depressed at the base. Coxae, trochanters, tibiae, 

 and tarsi densely covered with a short pubescence. 



The male has the pubescence on the front of the head golden, the mandibles reddish,, 

 and the hind tarsi testaceous in the middle. 



The petiole in some specimens is for the greater part red, in others the base only 

 is black above. 



J 



D. Metanotum furrowed in the middle ; hind trochanters with a stout spine. 



(Species 15.) 



15. Trypoxylon spinosum, (Tab. IV. figg. 8, 8 a ; 8 b, c? 



Nigrum, petiolo abdominisque segmento primo rufo-maculatis, medio tarsorum posticorum luteis ; facie, clypeo 

 lineaque mesonoti aureo-Mrtis ; thorace cinereo et argenteo-piloso ; vertice rugoso ; metanoto excavato r 

 transverse striato ; trochanteribus posticis spina longa armatis ; alis fuseo-maculatis. c? 2 • 



Long. 12-14 millim. 



Hal. Mexico, Presidio (Forrer). 



Head nearly as wide as the thorax ; front and vertex convex, not depressed, rugosely 



punctured ; a shallow furrow uniting the ocelli ; eyes at the top separated by a little 



more than the length of the third antennal joint, margined above the incision, the 



latter rounded at the end. Clypeus shining, punctured, rather flat, not keeled ; a small 



rounded incision in the centre, the incision itself having a small thick tubercle in its 



middle. Mandibles reddish at the base ; finely rugosely punctured. The golden 



pubescence is thick and moderately long, and extends from the eye-incision to the apex 



of the clypeus. There is a moderately sparse fuscous pubescence on the vertex, and 



behind the eyes there is a longer and thicker silvery pubescence. Antennae thick, 



black, covered with a cinereous microscopic pile. Prothorax above of equal width, but 



in the middle with a slope from the base to the apex above, and without any projecting 



angles laterally. Mesonotum shining, closely and somewhat strongly punctured, the 



pleurae, if anything, more strongly and closely so ; the oblique furrow shallow. 



Metanotum olosely transversely striated ; a broad V-shaped depression in the centre. 



The pronotum in front, a line along the base of the mesonotum, and the metanotum 



(especially at the base and apex) broadly clothed with silvery, inclining to golden, hair ; 



the rest of the thorax with short fuscous hair. Abdomen alutaceous, from the second 



