. The Cambridge natural history. Zoology. HYMENOPTERA connected that it is not easy to count them. The abdomen is, in the great majority, of very pecidiar construction, and allows the Insect to curl it completely under the anterior parts, so as to roll up into a little ball; the dorsal plates are very strongly arched, and seen from beneath form a free edge, while the ventral plates are of less hard consistence, and are connected witii the dorsal plates at some distance from the free edge, so that the abdomen appears concave beneath. In the anomalous genus Cleptes the abdoi::en is, however, sim
. The Cambridge natural history. Zoology. HYMENOPTERA connected that it is not easy to count them. The abdomen is, in the great majority, of very pecidiar construction, and allows the Insect to curl it completely under the anterior parts, so as to roll up into a little ball; the dorsal plates are very strongly arched, and seen from beneath form a free edge, while the ventral plates are of less hard consistence, and are connected witii the dorsal plates at some distance from the free edge, so that the abdomen appears concave beneath. In the anomalous genus Cleptes the abdoi::en is, however, similar in form to that of the Aculeate Hymen- optera, and has four or five visible seg- ments, instead of the three or four that are all that can be seen in the normal Chrysididae. The larvae of the Euby- fiies have the same number of segments as other Hymenoptera Petiolata. The difference in this re- spect of the perfect Chrysididae from other Petiolata is due to a greater number of the terminal segments being indrawn so as to form the tube, or telescope-like structure from which the series obtains its name. This tube is shown partially extruded in Pig. 1 ; when fully thrust out it is seen to be segmented, and th]-ee or four segments may be distinguished. The ovipositor proper is concealed within this tube; it appears to be of the nature of an imperfect sting; there being a very sharply pointed style, and a pair of enveloping sheaths ; the style really consists of a trough-like plate and two fine rods or spiculae. There are no poison glands, except in Cleptes, which form appears to come very near to the Aculeate series. Some of the Chrysi- didae on occasions use the ovipositor as a sting, though it is only capable of infiicting a very minute and almost innocuous wound. Although none of the Ptuby-flies attain a large size, they are usually very conspicuous on account of their gaudy or brilliant colours. They are amongst the most restless and rapid of Insects ;. Fig. 1.—Chrysis
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Keywords: ., bookauthorsh, bookcentury1800, bookdecade1890, booksubjectzoology
