2 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
incurved. The frontal bristles usually much shorter and weaker in . 
the male than in the female. Antennae short, the third segment not 
twice as long as its width at base, with the lower apical angle 
rounded, the upper one rather acute, the arista subnude; proboscis 
short and stout; palpi normal. Thorax with the usual two pairs of 
dorsocentral bristles, the anterior pair near the suture; the prescu- 
tellar acrostichals undeveloped; scutellum usually with but the basal 
pair of bristles present, the disk centrally bare, the sides short haired. 
Wing always with a large preapical black mark that emits a number 
of rays of variable width and extent, the third vein sometimes with 
some microscopic hairs above basally and more extensively below. 
Legs normal, mid femur sometimes with bristles on the ventral or 
anterior surface in at least the males of some species, the hind tibia 
with usually some microscopic anterodorsal setulae. 
Several species of very similar appearance to the typical forms 
have been removed from the genus by different writers because they 
have a pair of short apical bristles on the scutellum and but two 
pairs of incurved infraorbital bristles on the frons. I disregard 
these two characters as generic criteria as the apical scutellars are 
sometimes very small, and in some typical species of 7rypanea the 
anterior pair of infraorbitals is very minute or even lacking in par- 
ticular specimens. I believe by following this rule we may arrive 
at a better understanding of the genus. 
In almost all the species with the characteristic starlike preapical 
black mark on the wing there is a small, round, hyaline mark or spot 
immediately below the extreme tip of the second vein, whereas in 
the other group of species in which there are numerous brown marks 
on the basal half of the wing there is no small spot at this point, but 
instead there is one above the tip of the second vein. If the posi- 
tion of this spot and the type of the other wing markings are ac- 
cepted as generic criteria, rather than the bristling of the frons 
and the scutellum, then it appears to me that we have a more nat- 
ural arrangement of the species involved. This course is therefore 
adopted herein. 
KEY TO THE SPECIES OF TRYPANEA 
OD IVT AST gs ne Ra gd at a ws tac nse Fea an) ee la 2 
1 Sey 0042 25s ee Em SN laa pe OREN eye a CUT SVD SOR A oIEPH Bos Re DL Lyte sy ACU Bh ARS 6, Soh GE SR 20 
2. Scutellum with four bristles, the apical pair much shorter than the basal. 3 
Scutelum with but one pair of bristies, the apical pair undeveloped___. 4 
38. Two of the dark rays across the apical half of the discal cell of the 
wing extending over the fifth vein, the outer one attaining the wing 
margin, and a small hyaline spot at apex of the second vein 
Ae BE SE eet 2 Ue atk oe ek ee eugenia (van der Wulp) 
One dark ray across the apical half of the discal cell, which extends 
over the fifth vein to the wing margin, and a large wedge-shaped 
hyaline mark beyond the apex of the second vein (fig. 1, b). 
stigmatica (Coquillett) 
