Page:Jardine Naturalist's library Entomology.djvu/258

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252
SYSTEMATIC ARRANGEMENT.

the express purpose of securing an increase of power, we perceive how admirably adapted these creatures are for a kind of motion which must often have excited surprise by its extent and rapidity.

The tibiæ are thickly armed with spines, some of which are merely processes of the crust, and others are implanted. Of the former there are two rows, one on each side, leaving a groove between them; and of the latter are those on the lower angles of the tibiæ.

Of this family we shall figure, as examples, two British species, and a few remarkable foreign forms.


ACRIDA VIRIDISSIMA.

Plate XIII. Fig. 1.

Gryllus viridissimus, Linn.—Donovan's Brit. Ins. IV. Pl. 130. Locusta viridissima, Leach.—Conocephalus virid. Samouelle.—Curtis' Brit. Ent. I. 82.

Acrida has antennæ as long as the body, setaceous, the basal joint dilated, second short, third rather longer; maxillæ with three small teeth at the tip, the palpi having the terminal joint longest and truncate at the extremity; labrum orbicular, dilated at the base; mentum narrowed anteriorly; the exterior lobes of the ligula dilated and palpiform; posterior tarsi with the penultimate joint short and bilobed, the first having a lobe on each side near the base.

This genus contains all the British insects that can be referred to the family of the Gryllidæ. Although they do not exceed a dozen, they are so diversified in character that it is only by a pretty general definition that they can be comprehended in the same generic