290 NEW YORK STATE MUSEUM 
bb Mandibles suctorial, without teeth at middle or at base 
ec Apex of the abdomen not armed with four hooks...Dytiscidae 
ce Apex of the abdomen armed with four hooks....... Gyrividae 
aa Tarsi never with more than a single claw; in some species the legs | 
entirely wanting 
b Cerci present as jointed appendages, in some cases hardly more than 
a jointed tubercle 
ce Larvae long, wirewormlike; the caudal end of the abdomen strongly 
chitinized; larvae Terrestrial... .- 2) 0. = «6 eee Elateridae | 
cc Larvae soft bodied, not wirewormlike; the caudal end of the abdo- 
men not more strongly chitinized than the remainder of the body © 
d Hyes in groups of five or six 
e Larvae terrestrial, feeding in fungi Ce ee ee Scaphidiidae 
ee Larvae aquatic : 
f Byes in eroups of five....:0.. 205 2ece. eee Haliplidae | 
ff EXyes In Srouns OF SIR Yiesas. SEG eto cee Hydrophilidae 
dd Eyes in groups of four, two, or none; larvae terrestrial 
e Labrum present, distinct; body frequently lepismoid in form 
Silphidae 
ee Labrum wanting; body not lepismoid in form, the sides sub- 
parallel 
f Eyes present, usually in groups of four..Staphylinidae 
ff AYES. WaMEING ...0.5 choose dw «aiese see eee ee Histeridae 
Sb Cerci wanting 
c Larvae without thoracic legs 
d Head broader than the remainder of the body; the Gay 
depressed; larvae wood borers 
e Maxillary palpi with three or four segments; the labial palpi 
with three segments; eyes frequently present 
Cerambycidae 
ee Maxillary palpi with two segments; the labial palpi minute, 
unsegmented; eyes usually wanting....... Buprestidae 
dd Head not broader than if as broad as the remainder of the body; 
the body cylindrical; the larvae infesting seeds... Bruchidae 
ec Larvae with distinct thoracic legs 
d@ Larvae scarabaeoid, that is, white grub-like, in form 
e Eyes present 
f Eyes six in number; laryae case-bearers 
Chrysomelidae 
ff Eyes two in number; larvae not case-bearers Trox 
Scarabaeidae 
ee Eyes wanting, or if present, usually of not more than a single 
ocellus 
f Antennae three jointed, minute, hardly projecting beyond the 
side of the head; larvae usually small......... Ptinidae 
ff Antennae two to six jointed, never minute, usually as long 
as, or longer than, the mandibles; larvae usually large 
Lucanidae 
Scarabaeidae 
dd Larvae not scarabaeoid in form 
é Apex of the abdomen not more strongly chitinized than the 
remainder nor produced into one or two prominent projec- 
tions 
