Spider lines

Spider \Spi"der\, n.[OE. spi[thorn]re, fr. AS. spinnan to spin;
   -- so named from spinning its web; cf. D. spin a spider, G.
   spinne, Sw. spindel. See {Spin}.]
   1. (Zool.) Any one of numerous species of arachnids
      comprising the order Araneina. Spiders have the mandibles
      converted into poison fangs, or falcers. The abdomen is
      large and not segmented, with two or three pairs of
      spinnerets near the end, by means of which they spin
      threads of silk to form cocoons, or nests, to protect
      their eggs and young. Many species spin also complex webs
      to entrap the insects upon which they prey. The eyes are
      usually eight in number (rarely six), and are situated on
      the back of the cephalothorax. See Illust. under
      {Araneina}.
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   Note: Spiders are divided into two principal groups: the
         Dipneumona, having two lungs: and the Tetrapneumona,
         having four lungs. See {Mygale}. The former group
         includes several tribes; as, the jumping spiders (see
         {Saltigradae}), the wolf spiders, or {Citigradae} (see
         under {Wolf}), the crab spiders, or {Laterigradae} (see
         under {Crab}), the garden, or geometric, spiders, or
         {Orbitellae} (see under {Geometrical}, and {Garden}),
         and others. See {Bird spider}, under {Bird}, {Grass
         spider}, under {Grass}, {House spider}, under {House},
         {Silk spider}, under {Silk}.
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   2. (Zool.) Any one of various other arachnids resembling the
      true spiders, especially certain mites, as the red spider
      (see under {Red}).
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   3. An iron pan with a long handle, used as a kitchen utensil
      in frying food. Originally, it had long legs, and was used
      over coals on the hearth.
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   4. A trevet to support pans or pots over a fire.
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   5. (Mach.) A skeleton, or frame, having radiating arms or
      members, often connected by crosspieces; as, a casting
      forming the hub and spokes to which the rim of a fly wheel
      or large gear is bolted; the body of a piston head; a
      frame for strengthening a core or mold for a casting, etc.
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   {Spider ant}. (Zool.) Same as {Solitary ant}, under
      {Solitary}.

   {Spider crab} (Zool.), any one of numerous species of maioid
      crabs having a more or less triangular body and ten long
      legs. Some of the species grow to great size, as the great
      Japanese spider crab ({Macrocheira Kempferi}), measuring
      sometimes more than fifteen feet across the legs when they
      are extended.

   {Spider fly} (Zool.), any one of numerous species of
      parasitic dipterous insects of the family {Hippoboscidae}.
      They are mostly destitute of wings, and live among the
      feathers of birds and the hair of bats. Called also {bird
      tick}, and {bat tick}.

   {Spider hunter} (Zool.), any one of several species of East
      Indian sunbirds of the genus {Arachnothera}.

   {Spider lines}, filaments of a spider's web crossing the
      field of vision in optical instruments; -- used for
      determining the exact position of objects and making
      delicate measurements. Fine wires, silk fibers, or lines
      on glass similarly placed, are called spider lines.

   {Spider mite}. (Zool.)
      (a) Any one of several species of parasitic mites of the
          genus {Argas} and allied genera. See {Argas}.
      (b) Any one of numerous small mites injurious to plants.
          

   {Spider monkey} (Zool.), any one of numerous species of South
      American monkeys of the genus {Ateles}, having very long
      legs and a long prehensile tail.

   {Spider orchis} (Bot.), a European orchidaceous plant
      ({Ophrys aranifera}), having flowers which resemble
      spiders.

   {Spider shell} (Zool.), any shell of the genus {Pteroceras}.
      See {Pteroceras}.
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