34 HYMENOPTERA. 



PCECILOSOMA. 



Poecilostoma, Dahlbom, Consp. Tenthr. p. 5 (1835). 

 Empyria, Brulle, Hymen, iv. p. 666. 



This genus is of small extent, and is not of very wide distribution. Nine European 

 species have been described, two North- American, and one is known from Chili. The 

 typical species have black bodies and legs ; and the white markings on the edges of the 

 abdominal segments are characteristic. The black species are difficult to separate, unless 

 attention be paid to structural details. 



1. PceciloSOma mexicamim. (Tab. II. figg. 9; 9 a, labium- b, antenna; 

 c, maxilla ; d, saw ; e, mandible.) 



Nigrum, nitidutn, pilosum, tegulis, pronoti limbo, genibus tibiisque anterioribus margine albidis ; calcaribus 



posticis brevibus, unguiculis dente subapicali armatis ; alis fumatis, costa et stigmate nigris. $ . 

 Long. 6-7 millim. 



Hob. Mexico, Milpas in Durango 5900 feet (Forrer). 



The antennse are somewhat longer than the head and thorax, but shorter than the 

 abdomen; they are thick, almost glabrous, the third joint nearly one fourth longer 

 than the fourth, the last shorter and thinner than the eighth. The front and vertex are 

 slightly shagreen ed ; the sutures on the vertex are deep but narrow ; the ocelli are 

 separated from the part behind them by a deep furrow. The frontal area proper is 

 obsolete; the lower ocellus has a short triangular furrow surrounding it behind; the 

 front projects between the antennse, ending in a sharp point in the middle, and hollow 

 on either side of this; the antennal fovea is large, deep, and round. Below each 

 antenna is a large, deep, somewhat roundish depression. The clypeus is incised, with 

 the edges acute ; with a strong glass it is seen to be pitted with round shallow 

 depressions ; the mandibles and sometimes the labrum are piceous; the mandibles have 

 a subapical tooth. The eyes are comparatively small ; the second radial cellule is a 

 little shorter than the first ; the transverse radial nervure is received a little in front of 

 the third transverse cubital. The first transverse cubital nervure is distinct; the first 

 cubital cellule is comparatively large ; the second is longer than the third, but much 

 narrower than it; in the second cubital cellule is a horny point; the recurrent 

 nervures are received a little in front of the cellules, the transverse median nearly in 

 the middle ; the accessory nervure in the posterior wings is appendiculate. The cenchri 

 are fuscous. 



Judging from the description, this species would appear to come close to P. inferen- 

 tium, Norton, of which only the male has been described ; but the present species 

 appears to have longer, antennae, those organs in P. inferentium being " short, not 

 longer than to scutellum." 



