. British dragonflies (Odonata). Dragon-flies; Odonata -- Great Britain. The Nymph. 35 imperfect rectal respiratory system.^ Between the pro- notum and the meso-notum in the full-grown n}-mph will be found a pair of large spiracles (Fig. ii, ) (some- times plainly visible), while another smaller pair occur just above the hind-legs. Immediately before emergence the former pair are probably open, and used for breathing atmospheric air. The eight pairs of abdominal spiracles appear to be functionless during the nymph-stage. In connection with the structure of the Dragonfl3'-nymph the most str
. British dragonflies (Odonata). Dragon-flies; Odonata -- Great Britain. The Nymph. 35 imperfect rectal respiratory system.^ Between the pro- notum and the meso-notum in the full-grown n}-mph will be found a pair of large spiracles (Fig. ii, ) (some- times plainly visible), while another smaller pair occur just above the hind-legs. Immediately before emergence the former pair are probably open, and used for breathing atmospheric air. The eight pairs of abdominal spiracles appear to be functionless during the nymph-stage. In connection with the structure of the Dragonfl3'-nymph the most striking point is the mask f'Fig. 13, ;//.), a peculiar modification of the labium, or lower lip, by means of which the creature catches its pre}'. The term mask is applied to this structure because it hides the lower part of the face. At rest, with the exception of the tip, the mask is out of sight (Figs. 11 and 12). The base is attached below the mouth ; the hinder half lies under the head and fore part of the thorax ; there is a joint in the middle, and the fore part lies under the hinder, bringing the base and tip together close to the mouth. Fjg. 13.—Side-view of FoRE Part of a Nymph with Mask in situ. II!., Mask: It., Hinge; Tip of Mask; , Movable Hook attached to Palpus. * The five anal appendages of the Libellulidcr vary much in size and shape, as also do the lamella; of the Ai^rio?iid(r. One or two of the latter are to be seen in Figs. 41, 45, 47, and 53, from which it will lie noticed that the differences are considerable, and it may be that wlien more is known of the Agrionine nymphs the lamella; may be found to be of use in helping to distinguish the sjiecies. D 2. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lucas, William John. London, L. U. Gill
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondo, bookyear1900
