. Elementary text-book of zoology. Zoology. 510 . ARACHNIDA. by a small valve-like flap, the genital operculurn] ; on the second abdominal segment are attached two peculiar comb-shaped structures, known as pectines. The latter are probably the remains of the appen- dages of the segment, and serve as tactile organs. The males are distinguished from the females by their broader chela? and longer post-abdomen. The females are viviparous. The development of the ovum takes place in the ovary, and the embryos have the rudiments of appendages on the pne-abdorneii (fig. 411). The Scorpions live in war
. Elementary text-book of zoology. Zoology. 510 . ARACHNIDA. by a small valve-like flap, the genital operculurn] ; on the second abdominal segment are attached two peculiar comb-shaped structures, known as pectines. The latter are probably the remains of the appen- dages of the segment, and serve as tactile organs. The males are distinguished from the females by their broader chela? and longer post-abdomen. The females are viviparous. The development of the ovum takes place in the ovary, and the embryos have the rudiments of appendages on the pne-abdorneii (fig. 411). The Scorpions live in warm countries, and leave their hiding-places at dusk. AVhen they run, the post-abdomen is bent upwards over the back. They seize their prey, , principally spiders and large insects, with their large chelate pedipalps, and sting them to death with their caudal poison-spine. Some species attain a very consider- able size, and their sting may even prove fatal to man. Fam. Scorpionidae. iScnrj>ii> ntropfpiix Schr., of small size and with only six eyes, in Italy. Androctonus ocnitaitiix Am., Bittlmx ttfer L. Order 7.—PSEUDOSCORPIONIDEA.* Arachnida of small size and resembling scorpions, but without caudal spine or poison gland. They breathe by means of trachece. The Pseudoscorpions are far smaller and FIG, 412.—Ooisium tromoMioides (r^rjne animal). A7, Pedi- more simply organised than the scorpions. palpus' They bear much the same relation to the true scorpions that the mites do to the spiders. In their form and the structure of their cheliceras and chelate pedipalpi they resemble the scorpions. On the other hand, the hind end of the segmented abdomen does not become narrow so as to form a post-abdomen, and is without a caudal spine and poison gland (fig. 412). They all possess spinning glands, the openings of which lie near the genital openings on the second abdominal ring. They possess only two or four ocelli, and respire by means of trachea?, which open by two pairs o
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
