262 HTMENOPTEEA. 



A. The basal segment of the abdomen gradually dilated to the apex and continuous 

 with the base of the second. (Species 1-40.) 



1. Females (the males known or not). (Species 1-20.) 

 i. The thorax broadly incised in the middle. (Species 1.) 



l. Mutilla arguta. (Tab. XIII. fig. 2, $ .) 



Capite aureo-hirto ; thorace ferrugineo, nigro-maculato ; abdomine irigro, ferrugineo- et aureo-maculato. $ . 

 Long. 3*5 millim. 



Sab. Panama, Bugaba (Champion). 



Head wider than the thorax, closely, rugosely punctured ; the vertex sparsely 

 covered with fuscous hair, the lower part with longer white hairs ; the front also with a 

 pale golden pubescence ; the vertex irregularly suffused with fuscous patches. The 

 eyes large, projecting, not reaching to the top of the head ; the head well developed 

 behind them and not much narrowed. The scape of the antennae bears a short silvery 

 pubescence, and the flagellum a pale microscopic pile ; the third joint is a little longer 

 than the fourth. The thorax broadest in front, narrowest towards the apex, the middle 

 contracted broadly ; the prothorax with a distinct neck at the base, the apical part 

 rounded in front ; at the base of the contracted middle part of the mesothorax are two 

 stout teeth ; the middle is rough, but without distinct teeth ; along the edge of the 

 median segment at the base are four sharp teeth of moderate length and a fifth shorter 

 blunt one. The median segment has a rounded semioblique slope. The upper part of 

 the thorax is finely and closely rugosely punctured, and covered with long fuscous hair. 

 The mesopleurse are excavated, shining, glabrous, very finely, longitudinally striated. 

 Abdomen a little wider than the thorax, finely coriaceous ; the base covered with long 

 white hair ; the middle and apical parts with the hair sparser and shorter ; the four 

 apical segments are also densely fringed with pale golden hair. The basal segment is 

 gradually dilated to the apex. The second segment at the base is blackish, the black 

 being cleft in two by a central ferruginous band, which is broad at the base, narrower 

 at the apex ; next comes a broad yellowish band, contracted in the middle ; the apex 

 is blackish suffused with ferruginous, the extreme apex in the middle with pale golden 

 hair. The third segment at the base is transversely striated. The legs (including the 

 femora) are covered with soft silvery hair. 



A variety (X) from the Volcan de Chiriqui (Champion) differs from the above in 

 coloration : the head behind and in the centre of the vertex is black ; the flagellum of 

 the antennae is black ; there is a broad black stripe down the middle of the thorax ; 

 the upper part of the mesopleurae is more or less blackish ; the basal part of the second 

 abdominal segment is black, with a broad ferruginous band down the centre, the black 

 being continued down the middle in a narrow band, dividing a broad irregular yellowish 

 band in two, the apex also black and wanting the fringe of golden hair; the third 



