. The Cambridge natural history. Zoology. ORTHOPTERA Hetcrogamia is replaced by an ocellus. The antennae are very elongate and consist of a large number of minute rings or joints, frequently about 100. The head is not inserted directly in the thorax, as is the case in so many Insects; but the front of the thorax has a very large opening, thus the neck between it and the head is of more than usual importance; it includes six cervical sclerites. The pronotum is more or less like a shield in form, and frequently entirely conceals the head, and thus looks like the most anterior part of the body ;
. The Cambridge natural history. Zoology. ORTHOPTERA Hetcrogamia is replaced by an ocellus. The antennae are very elongate and consist of a large number of minute rings or joints, frequently about 100. The head is not inserted directly in the thorax, as is the case in so many Insects; but the front of the thorax has a very large opening, thus the neck between it and the head is of more than usual importance; it includes six cervical sclerites. The pronotum is more or less like a shield in form, and frequently entirely conceals the head, and thus looks like the most anterior part of the body ; usually it has no marked angles, but in some of the apterous forms the hind angles are sharp and project backwards. In contrast to the pronotum the prosternmn is small and feeble, and consists of a slender lateral strip on each side, the two converging behind to unite with a median piece, the prosternum proper. None of these pieces of the ventral aspect of the prothorax are ordinarily visible, the side-pieces being covered by the inflexed head, and the median piece by the great coxae. In some of the winged Blattidae {Blahera, ) there is at the base of each anterior coxa a small space covered by a more delicate membrane, that suggests the possibility of the existence of a sensory organ there (Fig. 120, %)} At the base of—above the front coxa the pro- thoracic spiracle is situate. The meso- and meta-thoracic segments differ but slightly from one another; the notal or dorsal pieces are moderately large, while the sternal or ventral are remarkably rudimentary, and are frequently divided on the middle line. Connected with the posterior part of each sternum there is a piece, bent upwards, called by some anatomists the furca; when the sterna are divided the furca may extend forwards between them; in other ' This enigmatic structure is similar in position to tlie aural orifice of Locustidae (see Fig. 101) ; but it is closed by a transparent membrane, whereas the ear orifice of Lo
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
