426 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
part of the eye extending about half-way toward the posterior 
margin of the head, an elongate spot on posterior half of cheek 
(the lower half almost always not fully developed; the last two 
spots coalesce sometimes) ; antennae black (apical segments rarely 
rufescent), the basal segment yellow on the inside, and very often 
the second segment is similarly brownish yellow; palpi often 
greenish. Head behind eyes about as wide as through them, very 
rarely distinctly narrower; supra-antennal ridges generally fairly 
prominent; frontal fovea generally broader posteriorly. 
Thorax. — Black ; the following parts yellow : margin of pro- 
notum (often interrupted) broadening considerably on the lobes 
of collar, tcgulae, pronotal lobe, prosternum quite often com- 
pletely or in part, V-spot on prescutum (very rarely obscured), a 
short longitudinal line on mesoscutum on each side of posterior 
portion of prescutum (occasionally absent), mesoscutellum with 
its transverse extensions, post-tergite, upper margin of meso- 
epimcron in part, the meso-episternum rarely with one or more 
spots or an obtuse-angled band, the pectus often posteriorly with 
a small spot on each side of the median longitudinal suture, a 
minute spot usually behind each cenchrus on metascutum, meta- 
scutellum with its transverse extensions, except very rarely the 
upper margin of the meta-epimeron narrowly or broadly, except 
very rarely a spot on the meta-episternum, and the mcta-post- 
scutellum entirely or in greater part. jNIesoscutellum moderately 
convex; meso-episternum fairly sharply or quite sharply pointed. 
Abdomen. — Black; the following parts pale yellow, or brown- 
ish yellow, or sometimes light brown: basal tergum in greater 
part (generally with a minute brownish spot laterally about in the 
middle), sides of 2d, 3d, 4th, and 6th terga (rarely of all terga), a 
median longitudinal band on same (often absent on 6th), the 
5th tergum and very often the 6th entirely ox in greater part, the 
two apical terga rarely, and the venter down to the ovipositing 
apparatus (rarely entirely). 
Legs. — Yellow, or yellowish (tibiae and tarsi often greenish) ; 
the following parts black: anterior coxae as a rule slightly at base 
outside, the intermediate from slightly at base to almost entirely, 
and the posterior except as a rule a small apical portion, the mid- 
dle femora as a rule at apex above and rarely taking the form 
