. A manual for the study of insects. Insects. COLEOPTERA. 525 The best way to obtain specimens is to sweep the vege- tation growing on the bottom of a quiet pool with a dip- net. The larger of our common species belong to Cybister (Cy-bis'ter), Dytisctis (Dy-tis'cus), and al- lied genera. In Cybister the little cups on the under side of the tarsal disks of the male are similar, and arranged in four rows. In Dytiscus and its allies the cups of the tarsal disks vary in size. Figure 633 represents a common species of Dy- tisCUS. Fig. 633. The most common of the diving-beetles that are of medium s
. A manual for the study of insects. Insects. COLEOPTERA. 525 The best way to obtain specimens is to sweep the vege- tation growing on the bottom of a quiet pool with a dip- net. The larger of our common species belong to Cybister (Cy-bis'ter), Dytisctis (Dy-tis'cus), and al- lied genera. In Cybister the little cups on the under side of the tarsal disks of the male are similar, and arranged in four rows. In Dytiscus and its allies the cups of the tarsal disks vary in size. Figure 633 represents a common species of Dy- tisCUS. Fig. 633. The most common of the diving-beetles that are of medium size belong to the genus Acilius (A-cil'i-us). In this genus the elytra are densely punctured with very fine punctures, and the females usually have four furrows in each wing-cover (Fig. 631). There are also common diving-beetles that are of about the same size as the preceding, but which have the wing- covers marked with numerous very fine transverse stritne; these belong to the genus Colymbetes (Col-ym-be'tes). Of the smaller diving-beetles, measuring less than one fourth of an inch in length, miany species can be found in almost any pond. These represent many genera. Family Gyrinid^ (Gy-rin'i-dae). The Whirligig-beetles, As familiar to the country rover as the gurgling of the brook, or the flecks of foam on its " golden-braided centre," or the trailing ferns and the rustling rushes on its banks, are these whirligigs on its pools. Around and around each other they dart, tracing graceful curves on the water, which vanish almost as soon as made. They are social fellows, and are almost always found in large numbers, either swim- ming or resting motionless near together. They rarely dive, except when pursued; but are so agile that it is extremely. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Comsto
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinsects, bookyear1895
