1880.] 403 [Patton. 
of C’. compacta Cress. ? is similar to that of compar @ in outline, but 
the lateral sinuations are much deeper, and the side lobes of the 
labrum are separated from the median portion by a distinct angle 
which places them upon a lower plane; the median lobe is dark tes- 
taceous, the side lobes semi-transparent. In the male of compacta, 
the labrum is not enlarged; the median lobe of the clypeus is greatly 
narrowed, almost pointed, at the tip. In Cerceris fumipennis, the 
labrum is unusually large in the 3; in the @ it differs from all others 
examined, in having only one broad sinuation asin Hucerceris 2. 
Of fumipennis, C. wnicincta Tasch., Giebel’s Zeit. xLtv, 397, ? 
(1875), is a synonym. 
Cerceris mandibularis n. sp. 
?. Length 9 mm., expanse 15 mm. Slender, the wings long. 
Black, base of mandibles, sides of face, two dots on clypeal process, 
spot below insertion of antennae, and spot on scape beneath, two 
dots on scutellum, tips of femora, tibiae and tarsi, of four anterior 
legs, stripe on tibiae of posterior legs, and narrow fasciae on the 
second, third, fourth and fifth segments of the abdomen (that on the 
second segment broadest, and that on the fifth segment slightly inter- 
rupted, and all the fasciae narrowed on disk), yellow. Tips of 
mandibles, basal joints of flagellum beneath, tip of the apical joint 
of antennae, the tegulae and tip of posterior femora, testaceous. 
Wings subhyaline, the anterior margin beyond stigma clouded, vio- 
laceous. ‘The mandibles expanded on the middle of the inner edge, 
the expansion broadest in the middle, and bearing three slight teeth. 
Side lobes of clypeus silvery pubescent, margin of median lobe 
armed with two blunt teeth between which is a broad expansion; 
base of clypeus bearing a broad truncated process, the face of the 
truncation flanged beneath, and forming an arched, slightly exca- 
‘vated and highly polished surface. Body strongly punctured; a 
sharp ridge between antennae, enclosure of metathorax puncto-stri- 
ate; first segment of abdomen longer than broad, with the appear- 
ance of a slight sinus in the middle of the lateral margin when 
viewed from above, the segment only half the width of the following 
seements; the sinus in the sixth ventral segment no deeper than it 
is broad at the apex. Waterbury, Conn., Aug. 14th. 
3. Face below antennae, dot on tegulae, spot on posterior coxae, 
the four posterior trochanters, posterior femora beneath, and the pos- 
