. A text-book of invertebrate morphology. Invertebrates. TYPE TRAOEEATA. 485 clawlike and is perforated by the duct of a poison-gland. Each trunk-segment, of which there may be over a hundred, bears but a single pair of appendages, there being no compound segments as in the Diplopoda. Each leg is as a rule seven-jointed, the coxal joints of i those of the same segment being widely separated, and there is no modifica- tion of the seventh pair to serve as copulatory organs, though the pair of the penultimate segment are much reduced in size and lie at the sides of „ „„„ . „ . Pig. 323.—Antekior
. A text-book of invertebrate morphology. Invertebrates. TYPE TRAOEEATA. 485 clawlike and is perforated by the duct of a poison-gland. Each trunk-segment, of which there may be over a hundred, bears but a single pair of appendages, there being no compound segments as in the Diplopoda. Each leg is as a rule seven-jointed, the coxal joints of i those of the same segment being widely separated, and there is no modifica- tion of the seventh pair to serve as copulatory organs, though the pair of the penultimate segment are much reduced in size and lie at the sides of „ „„„ . „ . Pig. 323.—Antekior Por- the reproductive orifice. tion of a Chilopod. Stigmata are usually wanting in the at = antennae, first three trunk-segments, but occur in ''**' = maxilla. a certain number of the others, lying "'^^ = second maxilla. •^ " mxp = maxiUiped. usually laterally between the segments except in Scutigera, in which they have a dorsal position. They open into branched tracheal trunks which usually an- astomose with one another, though in Scutigera they open into sacs from which a large number of simple unbranched tracheal tubes arise arranged in a bunch as in the Diplopoda. Crural glands occur on the coxal joints of several of the posterior appendages. The nervous system is arranged as in other Myriapods, and simple eyes are usually present, in Scutigera only being closely aggregated together to form a faceted eye. This, however, is not a compound ej^e exactly similar to that of the Insects, but is to be regarded simply as a close aggregation of simple eyes. The reproductive organs are usually paired, and the sexes separate. The ducts unite before opening to the exterior, so that there is but a single opening situated on the antepenulti- mate segment of the trunk, the appendages of which are greatly reduced in size. The embryos of Scolopendra and Geophilus leave the egg with almost the same number of ap- pendages as the adult, while those of Scutigera and Lith
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1894
