It is impossible here to deal with this sub-family in detail. Some of its members must be familiar enough to everybody, and the reader is recommended to spend an hour of a warm autumn day in watching them depart on the ballooning excursions, of which a description has been given (see p. [341]), from the knobs which surmount iron railings in a sunny spot. Among them he is pretty sure to find the genus Erigone—containing some of the largest members of the group—strongly represented.
In some species the male presents a remarkable difference from the female in the structure of its cephalothorax, which has the head region produced into eminences sometimes of the oddest conformation. An extreme example is seen in Walckenaera acuminata, a fine species in which the male caput is produced into a sort of spire, bearing the eyes, and nearly as high as the cephalothorax is long (Fig. [209], 3).
(vi.) The Formicinae include only two genera, Formicina (South Europe) and Solenysa (Japan). They are somewhat ant-like in appearance.
(vii.) The Linyphiinae are closely allied to the Erigoninae, but the legs are usually armed with spines, and very commonly the female has a dentated claw at the end of the pedipalp.
We include here about thirty genera of spiders of moderate or small size, living for the most part on bushes or herbage. The characteristic Linyphian web is a horizontal sheet of irregular strands, anchored to neighbouring twigs or leaves by cross threads in all directions, and the spider generally lurks beneath the web in an inverted position. Some of the larger species are very familiar objects, Linyphia triangularis being one of the most abundant English spiders, filling furze and other bushes with its extensive spinning work.
The sub-family may be roughly divided into three groups, of which the first is small, consisting of only three exotic genera of one species each. Donachochara may be taken as the type genus. They are moderate-sized spiders with rather short legs, found in France and Holland.
The second group consists of a number of genera of small spiders, sober-coloured, and generally more or less unicolorous in brown, yellow, or black, living in herbage. The sexes are much alike, the males never exhibiting the excrescences on the caput so often met with in the Erigoninae. The genus Tmeticus may be considered the type. It includes about forty species, of which about half are British. They are mostly dull yellow or brown spiders, averaging perhaps the eighth of an inch in length. Allied genera which are represented in England are Porhomma (twelve species), Microneta (twelve species), Sintula (twelve species). The American cave-genus Anthrobia comes here.
The third and last group is that including Linyphia and allied genera. They are moderate-sized or small spiders with long spiny legs and particularly long tarsi. The abdomen is generally decorated. The caput is frequently rather prominent and crowned with hairs.
Of the large number of spiders which have been described under the generic name of Linyphia, Simon[[317]] only admits about fifty species. Ten are included in the British list. L. triangularis has already been mentioned, but there are other common species, as L. montana, L. marginata, and L. clathrata. The members of most of the associated genera are rather small in size. We may briefly mention Bolyphantes, Bathyphantes, Lephthyphantes, and Labulla, all of which include English species.[[318]]
Fam. 23. Epeiridae.—This family includes all the spiders which spin circular or wheel-like snares, the highest form of spider industry, together with a few forms so closely allied in structure to orb-weaving species as to be systematically inseparable from them. It is practically co-extensive with the Argiopinae, Tetragnathinae, and Nephilinae of Simon’s Argiopidae in the Histoire naturelle des araignées.[[319]]