1921] Huckett: Ovipositor of Anthomyian Genera 315 
the cephalic margin of the dorsal surface, very lightly for the remaining 
region, on the ventral surface spinulose along the cephalic margin and 
for a short distance caudad along the midventral line, the remaining 
region smooth. Intersegment three spinulose on both surfaces except 
for a posterior margin of smooth hyaline membrane. Intersegment 
four smooth throughout. 
Segment VI. Tergum thinly chitinized, completely encasing the 
dorsal region, cephalic margin ragged; accessory pieces present clothed, 
with numerous sete; marginals diverse, distributed closely together 
and irregularly; spiracles approximate, oblique, cephalad of the acces- 
sory pieces. Sternum reduced to two spherical chitinous areas adjacent 
to the caudal margin; marginals diverse scattered over the entire sur- 
face; conjunctiva adjoining the sternites densely spinulose, remainder 
smooth. 
Segment VII. Tergum similar in structure to segment VI except 
that the chitin along the mid-dorsal line is much thinner, dividing the 
tergum into lateral plates; accessory pieces present; the marginal 
region and the accessory pieces possess numerous short, stout, spines 
amongst which are scattered a few longer bristles. Sternum reduced to 
two ovoid chitinous pieces adjacent to the caudal margin, which are 
covered throughout their entire area with numerous short, stout, 
spines; marginals few, usually two; conjunctiva densely spinulose 
between the tergum and sternites and for a short distance cephalad, 
remaining region smooth. , 
Segment VIII. Tergum divided by a spacious hyaline discal area 
into two lateral plates which taper gradually to the cephalic margin; 
marginals surplanted by a row of stiff, short, spines. Sternum com- 
posed of two elongate sclerites attaining one-half the length of the 
segment, the apical third armed with stout, short spinules; conjunctiva 
spinulose along the caudal margin, smooth for the remaining region. 
Segment IX. Suranal plate subtriangular, setae approximate; sub- 
anal plate broadly spade-shaped, sete regular, setulz sparsely distrib- 
uted over the surface; cerci, small, knobbed, smooth, sessile; apicals 
short and stout, setulz confined to the club; sense organs tubercular, 
with sharp apical spines. 
Pegomyia unicolor Stein. 
Segments longer than the intersegments, sclerites glabrous on the 
dorsal surface, spinulose on the ventral, lightly chitinized throughout, 
armed with bunches of stout spines. Intersegments smooth, hyaline. 
Segment VI. Tergum lightly chitinized, hyaline, slightly thickened 
around the caudal margin; accessory pieces present, armed with numer- 
ous stiff bristles; marginals stout, equal, regular, usually eight in 
number, distributed dorsad; spiracles the width of the sternum apart, 
oblique, orifices surrounded by a broad brim or margin, situated in the 
conjunctival membrane. Sternum short, conical, attaining one-third 
the length of the segment, sparsely covered with spinules; marginals 
approximate, in a semi-circle around the margin; conjunctiva smooth, 
hyaline, the caudal border with a few stout sete. 
