1958] 
Carpenter — Mexican Snake flies 
57 
genus : the anterior half dark brown or black, the posterior 
half lighter brown with four streaks of dark brown extend- 
ing towards the posterior border. The antennae are light 
brown in the holotype but, except for the first two seg- 
ments, are dark brown or black in the paratypes; the 
prothorax is brown to dark brown or black except for the 
anterior border, which is very light; the dark portion 
has the irregular dark and light brown markings character- 
istic of the genus. Mesonotum dark brown or black (para- 
types) with a median, very light brown spot; mesoscutellum 
light brown; metanotum marked like mesonotum except 
that the median light brown spot extends to the anterior 
margin of the segment and includes some white. Abdominal 
tergites dark brown or black laterally, with a median light 
stripe extending continuously along all tergites; the light 
stripe is mostly light brown but includes some white at the 
anterior and posterior edges of the genus Inocellia. The 
antennae are 7 mm. long and consist of 60 to 61 moniliform 
segments; the individual segments (see figure 6) areasyme- 
trical: on one side (the surface toward the other antenna) 
there is a cluster of three (rarely, four) long setae arising 
from nearly the same spot; this side of the antenna seg- 
ment has a somewhat flattened appearance- Each antennal 
segment has a ring of 25 long setae, arising on the distal 
half of the segment ; slightly proximally, near the middle of 
the segment, is a ring of 14 to 16 short setae which project 
distally. A few other setal sockets can be observed near 
the base of the cluster of three setae mentioned above. 
The terminal antennal segment is about twice as long 
as the others and lacks the peculiarities of the other seg- 
ments ; it bears about thirty setae. The prothorax is some- 
what shorter than the head; the ectoproct has rounded 
posterior margins, somewhat as in 7- longicornis ; the gon- 
ocoxites of the ninth segment have the distal margin folded 
inward forming a curved tooth, which is similar to that 
in longicornis. 
The female is unknown. 
Holotype ( $ ) : near Hidalgo, Tamaulipas, Mexico ; March 
27, 1938 (collected by C. C. Plummer). In the Museum of 
Comparative Zoology. 
