. The Cambridge natural history. Zoology. 386 ARACHNIDA—ARANEAE chap. a natural group, some of the families having apparently much closer affinities with certain of the Ecribellatae than with one another. This is especially evident in the case of the cribellate Oecobiidae and the ecribellate Urocteidae (see p. 392), which most authors unite in a single family. After all, the larger divisions of the order are not of great importance, and in the present cliapter Simon's linear arrange- ment of families will in the main be followed, except for the dis- tribution of the eight families which consti
. The Cambridge natural history. Zoology. 386 ARACHNIDA—ARANEAE chap. a natural group, some of the families having apparently much closer affinities with certain of the Ecribellatae than with one another. This is especially evident in the case of the cribellate Oecobiidae and the ecribellate Urocteidae (see p. 392), which most authors unite in a single family. After all, the larger divisions of the order are not of great importance, and in the present cliapter Simon's linear arrange- ment of families will in the main be followed, except for the dis- tribution of the eight families which constitute his Cribellatae ^ to the positions which a more general view of their structure would seem to indicate. Fam. 1. Liphistiidae.—Spiders with segmented abdomen, as shoivn liy the j^resence of a series of tergal plates. Sight spin- nerets in the middle of the ventral surface of the abdomen, far removed from the anal tubercle. Sternum long and narroiv. Eight coinijcwt eyes on a small eminence. Fourpulmonctry stigmata. This I'amily 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 Lij^histius alone. Some Arachnologists consider the genus Liphistius so different from Fia. 201. —Profile (jiat. size) and all Other Spiders as to constitute in ocular area (enlarged) of i»>/HS«ws j^gg^f ^ Sub-Order, for which, On account of the position of its spin- nerets, the name 3IES0THELAE has been suggested, all other fo
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