Coleoptera (ORDER OF INSECT A)

Of which over 80,000 species have been described. Beetles have masticating, often pincer-like, mouth parts, and have the front wings modified into horny wing-covers (elytra) which nearly or quite cover the soft abdomen, their inner edges meeting when at rest, and the outer edges curved around the abdomen. The hind wings, which alone are used in flight, are membranous and fold up under the elytra, when at rest. The head is sunk into the large and free prothorax. The antennæ are usually eleven jointed and peculiarly formed in the male. The development is by complete metamorphosis, from grub-like larvæ, usually furnished with thoracic legs and a few pro-legs, but some are apodal. The pupæ have freely projecting legs and are either suspended from objects or lie in the ground. There are four tribes based on the number of joints in the tarsus, Trimer a, Tetramer a, Heteromera, and Pen tamer a; but an extra rudimentary joint is present in the first two, thus raising their rank. Coleorhiza. Ti ue found at the bases of the roots of certain plants, as some gra es; membrane covering the embryo in the seeds of some monocotyledonous plants.