Consequently, black Kelpies became known as Barb Kelpies or Barbs. Walls rely on attachment between barbed wire barbs and/ or added pins between courses. Barbed tape is also characterized by the shape of the barbs. These are reduced to stiff, keratinous quills, resembling porcupine quills, with no barbs. Bristles are stiff, tapering feathers with a large rachis but few barbs. A number of brands, including Quickfit, have begun using threaded connections for hose barbs. It has a short or vestigial rachis (shaft), few barbs, and barbules that lack hooks. The heads of fishing spears usually feature barbs or serrated edges. Between the lyrates are twelve filamentaries, feathers of flexible silvery barbs. Old primary feathers wear away to reveal the blackish barbs beneath. Hornbills have prominent eyelashes (vestigial feathers with no barbs), as do ostriches. The two verbally sparred and traded humorous barbs while discussing films. The tip of the retractable organ is fleshy and lined with numerous small, sharp barbs. The sharp barbs penetrated with ease, but could not be pulled out. Both feather types have a central shaft with narrower barbs branching from that shaft.