STIZTJS. 103 



laterally; otherwise I cannot find tangible characters to separate it from the Guate- 

 malan form. Some specimens have the tibiae broadly lined with yellow, and the tarsi 

 are sometimes more or less yellow. The amount of yellow on the clypeus and inner 

 orbits of the eyes also varies, and the former is sometimes entirely yellow ; the femora 

 are sometimes broadly lined with yellow. 



The female does not differ much, if at all, in colour from the male. 



J 2. StizuS UneatUS. (Tab. V. figg. 7, 6 ; 7 a, head from in front ; 7 b, antenna.) 



Niger, dense albo-hirtus ; mesonoto flavo bilineato ; segmento mediali flavo nigro lineato ; alis hyalinis. c? • 

 Long, fere 9 millim. 



Hab. Mexico, Atoyac in Vera Cruz {Schumann). 



Antennae yellowish beneath ; the scape of a purer yellow than the flagellum ; the 

 flagellum becoming gradually thicker to the eleventh joint; the sixth to the eleventh 

 joints broader than long; the eleventh with a short, sharp spine at the apex beneath; 

 the twelfth joint fully one half longer than the eleventh or thirteenth ; the latter 

 terminating in a sharp spine, which is obliquely bent downwards. Head densely 

 covered with a silvery sericeous pile and with long pale fuscous hair ; obscurely 

 pitted and almost shining ; narrower than the thorax ; the ocellar region not raised ; 

 a yellow heart-shaped spot on the inner side of the posterior ocelli; clypeus some- 

 what convex ; labrum rounded. Thorax silvery-pilose and covered rather closely with 

 long pale fuscous hair. The edges of the prothorax all round, the tubercles, a 

 large irregular mark on the mesopleura, incised in the middle above and more 

 widely so beneath, a large mark in the centre of the metapleura, two narrow 

 longitudinal lines in the centre of the mesonotum, a broader line along the sides 

 extending nearly to the tubercles, the tegulae, the scutellum, a triangular mark in 

 the centre of the median segment (and with a black — thick at the base, narrowed at 

 the apex — line inside of it), the greater part of the sides (the yellow being very wide 

 on the apex, reaching to the black central line), and the lateral spines, yellow. Median 

 segment punctured. Abdomen shining, punctured, closely covered with long pale 

 silvery hair ; all the segments banded with yellow at the apex ; the black on the 

 basal segment is incised on either side in the middle, leaving a square black part ; on 

 the second segment the black broadly projects, the black divided in the middle and 

 behind almost cut off from the basal portion by a yellow interrupted transverse line. 

 Legs yellow ; the coxae, trochanters, femora, and tibiae irregularly lined with black. 



3. StizilS flavUS. (Tab. V. figg. 9, 6 ; 9 a, head from in front ; 9 b, antenna ; 

 9 c, male organ.) 



Flavus, fusco-hirtus ; flagello antennarum superne, lineis 3 mesonoto, abdominisque apice infra, nigris ; alis 



hyalinis, nervis nigris. 3 . 

 Long. 10 millim. 



