Fig. 2. A. aculeatus. (A) Front end, in ventral view, showing the clefts (arrows) between coxae of legs 1 and 2 that convey the oral effluent to the gland openings. (B) Front end, in right lateral view, showing the gland opening (upper arrow), and the notch under it, by which the oral effluent and secretion are routed onto the carapace channel (lower arrow) (compare with Fig. 4). (C) Right carapace channel, laden with clear oral effluent. (D) Comparable to C, after secretion has been added to effluent. (E) Comparable to C, at the moment when a second dose of secretion (arrow) is being emitted from the gland opening into the fluid in the channel. (F,G) Transfer of defensive fluid from carapace channel to femur (arrow) of hindleg.