. A text-book of invertebrate morphology. Invertebrates. â TTPB TBAOHEATA. 505 on the other hand, membranous and the veins are for the most part arranged longitudinally, so that when at rest the wings are folded like a fan, though in some forms, such as the Crickets, in which the anterior wings are short, a trans- verse fold also occurs. In the female Cockroaches the ante- rior wings are very small, and the posterior ones wanting, and in the Walking Stick (Diapheromera)âso named from its resem- blance to a green or dead twig^âboth pairs are entirely want- ing. The antennae are usually long and
. A text-book of invertebrate morphology. Invertebrates. â TTPB TBAOHEATA. 505 on the other hand, membranous and the veins are for the most part arranged longitudinally, so that when at rest the wings are folded like a fan, though in some forms, such as the Crickets, in which the anterior wings are short, a trans- verse fold also occurs. In the female Cockroaches the ante- rior wings are very small, and the posterior ones wanting, and in the Walking Stick (Diapheromera)âso named from its resem- blance to a green or dead twig^âboth pairs are entirely want- ing. The antennae are usually long and filiform, and the legs strong and adapted to a terrestrial life, some forms, such as the Cockroach, being exceedingly active. In the Grasshop- pers, Locusts, and Crickets the femora of the last pair of legs are greatly enlarged and very muscular, serving for jumping, while in the Mole-cricket {Gryllotalpa), which burrows in the ground, the anterior pair is greatly enlarged and adapted for digging. As in the Earwigs, the metamorphosis is gradual. 3. Order Ephemeridse. The Ephemeridse, or May-flies (Fig. 234), are characterized by the remarkable brevity of their existence in the imago- stage, some forms existing but for a few hours, while others live for several days, the existence being merely long enough to ensure the accomplishment of the re- productive acts. The body is elongated and terminates in two or three elongated hairlike cerci, and on the thorax there are borne usually two pairs of wings, of which the anterior pair is considerably larger fig. 2SLâPotamant/ius than the posterior. The antennae are marginaius(tTomFACK. short, and the mouth-parts adapted for '^^°'' biting, though usually much reduced, since the imago takes no nutrition during its short existence. The first pair of legs is usually slender and directed forwards, being of little use in locomotion. An interesting structural peculiarity is the oc- currence of paired reproductive ducts which open by sep
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1894
