282 
COLEOPTERA. 
available here. While we have given a brief diagnosis of the families 
we know to be represented in India, we are not sanguine that the stu¬ 
dent will place every beetle in its family by consulting these diagnoses. 
Some of the larger families are distinct enough; for the rest if the char¬ 
acters obviously agree with any diagnosis, the beetle can probably be 
placed provisionally in that family ; if, as in many cases, the student 
abandons the task as hopeless, there is no remedy but to consult some 
work in which the diagnoses are given in fuller detail. 
Actually a large majority of the smaller obscurer Polymorphous 
beetles found will undoubtedly be new and while their characters may 
agree with known genera, they are likely not to and we must anticipate 
the formation of new groups of beetles when our fauna is better studied. 
Finally in this heterogeneous group above all, a good reference collec¬ 
tion is essential as the actual interpretation of the characters and their 
just appreciation is no easy matter and is only to be gained by practice 
and experience. The majority of the following families can usually 
be distinguished, so far as known Indian forms are concerned :— 
Hydrophilidce. —Antennae of three parts, fitting under head; a 
sternal spine often. Part aquatic. 
Pselaphidce. —Tarsi three-jointed. Elytra truncate. Abdomen of 
7 or less segments, not mobile. 
Staphylinidce. —Tarsi three-jointed. Elytra truncate. Abdomen 
7 or 8 mobile ventral segments. 
Sphceriidce. —Tarsi three-jointed. Antennae clubbed. Three ventral 
segments. 
Trichopterygidce. —Tarsi three-jointed. Wings fringed with hairs. 
Very minute beetles. 
Corylophidce. —Tarsi four-jointed, first joint very small. Wings 
hair-fringed. Very small. 
Scaphidiidce .—Tarsi five-jointed. Antennae with the five apical 
joints broadened. 
Histeridce. —Tarsi five-jointed. Elytra truncate. Short clubbed 
antennae. Hard compact beetles. 
Phalacridcv. —Tarsi five-jointed, fourth very small. Posterior 
coxae contiguous. 
Nitidulidce. —Tarsi five, jointed, fourth very small. Posterior 
coxae not contiguous. Elytra often abbreviate or truncate. 
Trogositidce. —Tarsi five-j ointed, first very small. Antennae with 
apical joints broadened on one side only. 
Erotylidce. —Tarsi five-jointed, basal three broadened, fourth small, 
fifth long (c.f. Chrysomelidce). Antennae clubbed. 
Coccinellidce .—Tarsi four-jointed, third very small. Antennae not 
clubbed. 
