After all, the larger divisions of the order are not of great importance, and in the present chapter Simon’s linear arrangement of families will in the main be followed, except for the distribution of the eight families which constitute his Cribellatae[[307]] to the positions which a more general view of their structure would seem to indicate.
Fam. 1. Liphistiidae.—Spiders with segmented abdomen, as shown by the presence of a series of tergal plates. Eight spinnerets in the middle of the ventral surface of the abdomen, far removed from the anal tubercle. Sternum long and narrow. Eight compact eyes on a small eminence. Four pulmonary stigmata.
Fig. [201].—Profile (nat. size) and ocular area (enlarged) of Liphistius desultor.
This Family includes a single genus and two species of large spiders (about two inches in length), one from Penang and one from Sumatra. Very few examples have been found, and these are more or less defective and in bad condition. In some respects, especially the distinct segmentation of the abdomen, this genus much more nearly approaches the Pedipalpi than do any others of the order. No other spider possesses more than six spinning mammillae, but it is possible that eight was the more primitive number, and that the “cribellum” (see p. [326]) of the so-called Cribellate spiders is derived from the pair now possessed by Liphistius alone.
Some Arachnologists consider the genus Liphistius so different from all other spiders as to constitute in itself a sub-order, for which, on account of the position of its spinnerets, the name MESOTHELAE has been suggested, all other forms falling into the sub-order OPISTHOTHELAE.
Fam. 2. Aviculariidae. (Mygalidae).[[308]]—Spiders with independent chelicerae, the paturon directed forward and the unguis or fang articulating in a vertical plane. The eyes are eight (except Masteria, six), usually compact, and situated on an eminence. Pedipalpi very leg-like, and palpal organs of male simple. No maxillae. Four pulmonary stigmata. Spinnerets normally four. No colulus.
The Aviculariidae inhabit the warmer portions of the world, and are entirely unrepresented in this country. The monster spiders which excite wonder in zoological collections belong to this group, as do the moderate-sized “Trap-door” Spiders which are found abundantly in the Mediterranean region.
The Family has been divided into about a hundred and fifty genera, nearly half of which, however, contain only a single species.
They have been grouped by Simon[[309]] into seven sub-families, Paratropidinae, Actinopodinae, Miginae, Ctenizinae, Barychelinae, Aviculariinae, and Diplurinae, of which the first three may be dealt with very briefly.