. The Australian zoologist. Zoology; Zoology; Zoology. TILLYARD AND FRASER. 381 be demonstrated, and it is on the evidence of larval characters that we rely for establishing these. These characters are:—Labium deeply concave and fitting over the face like a gas-mask, plentifully furnished with setae, both on mentum and lateral lobes; the latter with apposed borders biserrate, serrate or crenate; movable hook small and reduced; gizzard with four folds, each fold furnished with a single robust tooth. Family 1. Cordulegasteridae. (Figs. 11 & 12.). Fig. 11.—Wings of Cordulegasteridae (Corduleg
. The Australian zoologist. Zoology; Zoology; Zoology. TILLYARD AND FRASER. 381 be demonstrated, and it is on the evidence of larval characters that we rely for establishing these. These characters are:—Labium deeply concave and fitting over the face like a gas-mask, plentifully furnished with setae, both on mentum and lateral lobes; the latter with apposed borders biserrate, serrate or crenate; movable hook small and reduced; gizzard with four folds, each fold furnished with a single robust tooth. Family 1. Cordulegasteridae. (Figs. 11 & 12.). Fig. 11.—Wings of Cordulegasteridae (Cordulegaster annulatus Latr.), male. This family contains two large groups of dragonflies which vary so much in facies and detail, that until a few years ago they were considered as not being at all closely related, and it was only the discovery of the larva and an examination of its characters which proved beyond doubt the place of the Chlorogomphinae in the family Cordulegasteridae. The insects contained in these two groups agree in being of large and robust size, with head transverse and eyes more or less separated, although not to the same extent as in the Gomphidae. The larvae, on the other hand, are so closely similar that they are difficult to separate; the body is long and fusiform, tapering towards the end of abdomen; labial mask of the concave or "spoon" shape, with broad triangular, cupped lateral lobes, furnished with setae and a longish movable hook, and with the apposed margins deeply serrate and biserrate. This latter feature is of great importance, since we find it repeated in the following two families, Corduliidae and Libellulidae. The head is robust and armed with a projecting frontal plate, which it apparently employs for burrowing in sand; legs moderately long and not specialized for digging as in the Gomphidae] gizzard highly specialized, made up of 4 folds, each of which is furnished with a single robust tooth more or less spined on its free border
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1914
