AQUATIC INSECTS IN NEW YORK STATE 443 
the Corydalinae. The more important of the distinctive char- 
acters of the subfamilies are included in the following tables. 
TABLE TO SUBFAMILIES 
Adults | 
a Accessory veins of radial ‘sector on the front side of 
- vein Rs [fig. 23]; ocelli wanting; fourth segment of 
Peremonrommently. bilODed 2... 0c. . Sete cee neice en Sialidinae 
aa Accessory veins of radial sector on the posterior side 
of vein Re [fig. 24, 25, 26]; ocelli three; fourth seg- 
ment of tarsi obscurely or not at all lobed......... Corydalinae 
Larvae 
@ Anal prolegs wanting; lateral filaments only seven 
PoirseranOrdistinetly JOM. 15... swe ecw e we ees Sialidinae 
ad Anal prolegs one pair, provided with claws; lateral 
filaments eight pairs, slightly or not at all jointed. Corydalinae 
Egg masses 
a Beggs always in one Payer. [plc 28 ok cieca aeee oat. s Sialidinae 
aa Kegs in more than one layer [Dp1.52]..... 2.2.04 see vee! Corydalinae 
Eggs 
@ Distal pertion of micropylar -projection cylindric, 
twice as long as broad, joined to the egg by a short 
eat Ree eric oleae sleiche e's slviwie. ossie.e's bee wl aete cieieie Sialidinae 
ad Distal portion of micropylar projection nearly globu- 
lar, joined to the egg by a long neck [fig.20]...... Corydalinae 
Subfamily SIALIDINAE 
~The adult members of this subfamily are all much smaller 
than those of the Corydalinae; the ocelli are wanting; the acces- 
sory veins of the radial sector in both pairs of wings arise 
from R, and extend forward, giving the insect a very charac- 
teristic mode of flight; the fourth segment of the tarsi is promi- 
nently two lobed. 
The subfamily includes a single genus Sialis. 
statis Latreille 
Besides the characters of the subfamily given above, the fol- 
lowing additional generic characters should be added: 
Adult. Body and wings black or ferruginous; prothorax 
quadrangular, almost equal in width to the head, not so long as 
the mesothorax and metathorax combined; ocelli wanting; an- 
