44 
Psyche 
[Sept.-Dee. 
Leptogaster prior, n. sp. (Asilidae) 
(Plate II, Fig. 1) 
Length 12 mm., length of wing 7 mm. Evidently a fuscous 
species, the comparatively stout abdomen indicating a female. 
Palpi not preserved; proboscis two-thirds the head-height. 
Lower part of pleura together with the mesonotum and meta- 
notum darker than the upper pleura. Abdominal tergites darker 
than their sternites. Legs not annulate, but base of femora paler 
fuscous, outer part of hind femora and of hind tibia dark; hind 
tibiae enlarged distally, their pubescence plainly discernible in 
the specimen. Wings narrow and hyaline, the neuration well 
preserved, second vein arising before discal cell, fork of third 
vein arising beyond discal cell and continuing with only slight 
curve to wing-tip, the anterior side of the discal cell evidently 
angulate at the fork of the fourth and intercalary veins, fourth 
posterior cell petiolate. 
A single specimen from the R. D. Lacoe collection, accession 
series number 38131, belonging to the United States National 
Museum. Leptogaster differs from other Asilidae by its slen- 
der form, limited chaetotaxy, reduced anal angle of the wing, 
long claws and vestigial pulvilli. The shape of the second pos- 
terior cell is also distinctive, extending over the discal cell and 
pointed at its proximal end. Leptogaster bears much the rela- 
tion to the other Asilidae that the slender-bodied Systropinae 
do to the other Bombyliidae. The modern Systropus is elongate, 
nearly bare, long-legged, with anal angle and alulae of the wings 
reduced, and thus differs markedly from the stout furry bee- 
flies. Although the extreme in Systropus has not been found in 
the Tertiaries, Professor Cockerell has made known several 
other of the nearly bare and slender Bombyliidae and has com- 
mented on their comparative abundance in early times. 
Compared with some thirty recent species of Leptogaster in 
my collection, the Florissant specimen agrees exactly with fla- 
vipes Loew, in every detail of neuration, coloration and size. 
Flavipes is one of the commonest of the living Leptogasters and 
is widely distributed from Colorado to the Atlantic seaboard. 
Were the lives of the two not separated by the millions of years 
of time I would have placed the fossil with the living species. 
This is the species mentioned by Professor Cockerell in the En- 
tomologist, 1913, page 214, and by Doctor James in the Journal 
