20 NEUROPTERA. 
they are often quite late in appearing. No identification of a male Hetwrina is certain 
unless its terminal abdominal appendages have been examined and the determination 
based thereon, although in some species a high degree of probability may be reached 
without reference to those structures. For the females, however, very few structural 
characters are known to exist ; in some species we are uncertain whether the females 
are correctly referred to the corresponding males, while in other cases it seems 
impossible to find any constant differences between females of species whose males are 
readily distinguished. 
Bearing all these facts and difficulties in mind, we present a key to the species of 
Heterina known from the present fauna, in the hope that it will prove more exact 
than those previously published *. Since one has not unfrequently to attempt the 
identification of Hetewrine in which the apex of the abdomen is lost, some subsidiary 
characters have been introduced to afford aid in such cases. Finally, since not a 
generic or specific character appears to exist which does not suffer some percentage of 
variation, it will not be surprising if readers of this work find individuals which ‘“ do 
not fit” the key. It is claimed, however, that, so far as the present material goes, 
these characters seem less variable than those previously employed for this purpose. 
Key to the Mexican and Central-American Species of Heterina. 
§ I. Hind wings with but one row of cells between the lower sector of the 
triangle and the hind margin of the wing beyond the level of the apex of 
the quadrilateral. Labrum black, with a yellow spot each side. Male 
with a rounded brown spot on the tips of all four wings; female 
unknown... . . . . . eee eee ee ee wwe. OL, fuscoguttata. 
§ I. Hind wings with two rows of cells (not more) in a considerable part of 
the area mentioned in § J. Labrum variously coloured. 
Males. 
a. Inferior terminal abdominal appendages well developed, at least one-third 
as long as the superiors. 
6. Inferior appendages not, or but slightly, enlarged at the tip. 
c. Tips of the wings brown or uncoloured. 
d. Basal spot of both front and hind wings chiefly or wholly red when 
mature. 
* It should also be stated that, in drawing up this key, one or more specimens of the following South- 
American species have been studied, with the result that they all fall within §II.: duplex 3, simplex 3 2, 
sanguinea 3, rosea S 2, caja SQ, dominula 3, auripennis 3, hebe Sg, sanguinolenta ¢ 2, lesa 2, car- 
nifee 3 (22), longipes 3, moribunda 3, brightweli g. Of the 42 “species” of Hetwrina enumerated 
by Kirby in his Catalogue, 35 have been examined for this purpose. 
That the sections (§ I., I1., III.) are not to be regarded as of generic or subgeneric rank is shown by the 
fact that in at: least one species, majuscula, the male falls in one section, the female in another. 
