These spiders are all wanderers, spinning no snares, though they form a sort of silken cell or retreat, in which the female lays her eggs. Their habits are diurnal, and they delight in sunshine. They stalk their prey and leap upon it with wonderful accuracy. They invariably attach a thread at intervals in their course, and on the rare occasions when they miss their aim while hunting on a perpendicular surface, they are saved from a fall by the silken line proceeding from the spot whence the leap was made.
Fig. [215].—Attid Spiders. A, Salticus scenicus, ♂; B, Marpissa muscosa, ♀; C, Synemosyna formica, ♀; D, Ballus variegatus, ♀.
The movements of these spiders are sufficient to indicate their systematic position without entering upon structural details, but their eyes deserve a special mention. They are all dark-coloured and very unequal in size, and they occupy the whole area of the caput, usually forming a large quadrilateral figure. Four large eyes occupy the facies or “forehead,” the medians being especially large. Next come two very small eyes, behind the anterior laterals, and lastly two of medium size at the posterior corners of the caput.
This vast family does not lend itself easily to division into sub-families, and it will be impossible here to do more than indicate a very few of the multitudinous forms.
The most familiar British example is Salticus scenicus (Epiblemum scenicum), the little black and white striped spider to be seen hunting on walls and fences during the summer. Marpissa muscosa is the largest English species, measuring about half an inch. It has a brownish-yellow coloration, and is found, though not commonly, in similar situations. Attus pubescens affects grey stone walls, on which it is nearly invisible except when moving. The other British species are mostly to be found on trees and shrubs or among herbage, or hunting over bare sandy spots in the sunshine. A few (Marpissa pomatia, Hyctia nivoyi) are fen species. Hasarius falcatus is a handsome spider, common in woods in some localities.
The species differ much in their jumping powers; the Marpissas, for example, are not great leapers, but the little Attus saltator, found on sandhills, jumps like a flea, and the North American species Saitis pulex has a suggestive specific name.
Again, in this family there are mimetic forms resembling ants. Myrmarachne formicaria (Salticus formicarius) is found very rarely in England, but is not uncommon on the Continent.
Synageles and Synemosyna are allied genera. Phidippus is a genus well represented in America, and Ph. morsitans has already been mentioned (p. 365) in connexion with its poisonous reputation. Astia and Icius have American representatives (see pp. 381, 382), though the type species belongs to the Old World.