198 THE SPIDERS OF EPPING FOREST.
19. Tibiae, metatarsi and tarsi of legs I and II with
a row of long strong spines upon their
undersides .. .. .. Mimetidae
Legs I and II without such spines.. .. 20
20. Tarsi IV with a double row of short curved
spines upon their undersides. Remaining
joints of legs usually without spines.
Tibia of male palpus without apophysis.. Theridiidae
Tarsi without spines. Legs almost invariably
furnished with spines which, however,
are sometimes very minute and confined
to tibia IV. In this latter case the tibia of
the male palpus is almost always furnished
with an apophysis .. .. 21
21. Height of clypeus greater than length of ocular
area (except Tapinopa and Tapinocyba).
Falces without basal protuberances .. Linyphiidae
Height of clypeus not greater than length of
ocular area. Falces often with basal pro-
minence .. .. .. Argiopidae
22. Tube tracheae opening in two apertures close
behind the laminal tracheae .. .. Argyrotietidae
Tube tracheae opening in a single aperture
just in front of the spinners .. .. 23
23. Spinners normally arranged in a group .. Agelenidae
Spinners arranged in a transverse row beneath
the extremity of the abdomen, the long
spinners, corresponding to the superior
ones of the Agelenidae, at the end of the
row .. .. .. .. Hahnidae
24. Eyes in four unequal rows. Legs furnished
with numerous very long spines . . Oxyopidae
Eyes in three rows of 4, 2, 2, four in the front
row .. .. .. .. 25
25. Eyes of first row very large. Tarsal claws 2 .. Salticidae
Eyes of first row small. Tarsal claws 3 .. 26
26. Second row of eyes much shorter than the third.
Clypeus high. Tibia of male palpus with
an apophysis .. .. .. Pisauridae
Second row of eyes not much shorter than the
third. Clypeus moderate. Tibia of male
palpus without an apophysis .. .. Lycosidae
Note.—Pholcomma gibbum, a very minute Theridiid, has the eyes arranged
as in Pholcidae. The caput of the male in some cases is elevated and the
position of the eyes modified in consequence. Such species may be referred
to the family Linyphiidae or more rarely to the family Theridiidae.