. The biology of spiders. Spiders; Insects. FOSSIL AND PRIMITIVE SPIDERS 277 and the first pair are the shortest. The second pair are sometimes shorter and sometimes longer than the third pair. In this respect, as in its segmented abdomen, Liphistius recalls Protolycosa, in which the relative lengths are 4, 3=2, 1. The underside of the abdomen of the Liphistiidae is characterised by two very large segmental plates of chitin. C O 0 \. Fig. 96.—Sternum of Dolicho- sternum. After Rainbow. Fig. 97. — Heptathela kimurai. Underside of abdomen. After Kishida. The later segments are not so large nor c
. The biology of spiders. Spiders; Insects. FOSSIL AND PRIMITIVE SPIDERS 277 and the first pair are the shortest. The second pair are sometimes shorter and sometimes longer than the third pair. In this respect, as in its segmented abdomen, Liphistius recalls Protolycosa, in which the relative lengths are 4, 3=2, 1. The underside of the abdomen of the Liphistiidae is characterised by two very large segmental plates of chitin. C O 0 \. Fig. 96.—Sternum of Dolicho- sternum. After Rainbow. Fig. 97. — Heptathela kimurai. Underside of abdomen. After Kishida. The later segments are not so large nor conspicuous (Fig. 97). The two large plates cover the two pairs of lung-books and the genital opening. The possession of two pairs of lung- books and the absence of spiracular tracheae constitute a primitive feature, shared by the Liphistiomorphae and the Mygalomorphae. The female genital aperture has no trace of the outer epigynum, described in a previous chapter, which occurs in all other spiders. All that is visible is a pair of spermathecal apertures at the sides of the hind edge of the plate covering the second segment. The palpal organ of the male is, naturally, a feature to which one turns in expectancy, for the multitudinous forms which this organ takes throw much light, as we have already noted, on the relationship of the different families. The most remarkable condition is that shown by the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Savory, Theodore Horace, 1896-. London : Sidgwick & Jackson
Size: 1243px × 2010px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecti, booksubjectspiders
