. The Cambridge natural history. Zoology. 324 ARACHNIDA ARANEAE with hairs, but iii some genei'a the clothing is so sparse that they appear glossy, while in others they have a positively shaggy appearance. Stouter hairs or " bristles " are often present, and some of the joints are also often furnished with " spines," which in many cases are erectile. The tarsi of all spiders are furnished with terminal claws, usually three in number, though in some families (Drassidae, Thomisidae, etc.) there are only two. The two principal claws are paired and usually dentated, though the
. The Cambridge natural history. Zoology. 324 ARACHNIDA ARANEAE with hairs, but iii some genei'a the clothing is so sparse that they appear glossy, while in others they have a positively shaggy appearance. Stouter hairs or " bristles " are often present, and some of the joints are also often furnished with " spines," which in many cases are erectile. The tarsi of all spiders are furnished with terminal claws, usually three in number, though in some families (Drassidae, Thomisidae, etc.) there are only two. The two principal claws are paired and usually dentated, though the number of their teeth may be unequal. The third claw, when present, is always smaller, median, and inferior. In many spiders of climbing habits the place of the third claw is taken by a remarkable tuft of club-like hairs termed a "scopula" (Fig. 180, 5), by means of which they are able to cling to smooth surfaces where claws would be able to obtain no hold. In some species there is a special false articulation â the " onychium " â at the end of the tarsus to bear the claws. In the Cribellatae the metatarsus is always fur- nished with a comb-like organ, the "calamistrum," correlated with an extra spinning apparatus, the " cribellum," but this will be dealt with when we reach the systematic portion of the subject. The general direction taken by the legs, the comparative length of the different joints, their armature of hairs, bristles, and spines, and the number and conformation of the tarsal claws, are points of great importance in the classification of Flo, â Spider tarsi. 1, Tarsus of Epeira Aiov/mg three claws and supplemental serrate hairs {a) ; 2, tarsus of a Thomisid Spider, with two claws ; 3, 3a, lateral and dorsal view of tarsus of an Attid Spider, showing scopula at Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearanc
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
