AQUATIC INSECTS IN NEW YORK STATBH 291 
f Body densely covered with long, fine setae which are gener- 
ally barbed and frequently aggregated into a pencil at the 
posterior end of the body............... Dermestidae 
ff Body not densely covered with long, fine setae, or, if pres- 
ent, these are minute and never aggregated in the form of 
a pencil at the posterior end of the body. No account is- 
taken here of the strong black or brownish chitinized 
spines 
g Larvae aquatic . 
h Antennae as long as, or longer than, the thorax 
Dascyllidae 
- hh Antennae not as long as the thorax 
4 Larvae depressed, with the lateral margins of the seg-- 
ments greatly produced so as to conceal the ventral 
and lateral portions of the body when viewed from: 
above; with tracheal gills on the abdomen 
Parnidae 
ui Larvae cylindrical; without tracheal gills 
’ j Labrum wanting: each body segment usually with 
four tong, filiform appendages; eight abdominal 
tergum never with a pair of dorsal spines with. 
spiracles at their) base: a6 00.5.6) .. Haliplidae 
jj Labrum present; none of the body segments with. 
long, filiform appendages; eighth abdominal ter- 
gum with a pair of dorsal spines with spiracles 
at their base; larvae feeding on the roots of 
AQUATIC  DIAMUS woes. vale Chrysomelidae 
gg Larvae not aquatic 
h The lateral margins of the abdominal tergites dilated so: 
‘ as to conceal the plurae when viewed from above, the 
dilatations when elongate, narrowed toward the apex 
i Body convex, about twice as long as wide; lateral dila- 
tations blunt and covered with numerous minute 
REIT Os eee eisasrete ibid sok «ee cuajaiwnacsi o eos Endomychidae 
ii Body flattened above, distinctly more than twice as 
long as wide; the lateral dilatations frequently 
pointed and never covered with numerous minute 
Setae RIeah SC UCEN thet ata Cathe Rw nyel con iw etece et ee Lampyridae 
hh The lateral margins of the abdominal tergites not dilated 
so as to conceal the plurae when viewed from above 
i Body covered with strong, elongate, black or brownish,. 
chitinized spines 
j Median pair of spines of the eighth abdominal ter- 
gite long and modified into a faeci-fork for carry- 
ing the cast larval skins and faeci, umbrellalike 
OVERTURN DAC aes <s'e s ekw we e's Chrysomelidae 
jj Median pair of spines of the eighth abdominal ter- 
gite not longer than the others, and, if any are 
elongate, it is the median pair of the ninth ab- 
dominal tergite 
