. A manual of zoology. Zoology. I. CMUSTx\CEA: LEPTOSTRAGA. 427 Legion I. Lejilostraca. The Leptostraca connect the Phyllopoda with the higher groups. They have twenty-one somites, eight abdominal, eiglit thoracic, and five cephalic, and this and the openings of the genital dncts ally them to the Malacostraca. On the other hand the bivalve carapace covering the cephalothorax and part of the abdo- men, and the leaf-like thoracic feet, are phyllopodan. They have an antenual gland and a rudimentary shell gland; an elongate heart which extends through cephalothorax and abdomen; and com-. Ftg. 432.
. A manual of zoology. Zoology. I. CMUSTx\CEA: LEPTOSTRAGA. 427 Legion I. Lejilostraca. The Leptostraca connect the Phyllopoda with the higher groups. They have twenty-one somites, eight abdominal, eiglit thoracic, and five cephalic, and this and the openings of the genital dncts ally them to the Malacostraca. On the other hand the bivalve carapace covering the cephalothorax and part of the abdo- men, and the leaf-like thoracic feet, are phyllopodan. They have an antenual gland and a rudimentary shell gland; an elongate heart which extends through cephalothorax and abdomen; and com-. Ftg. 432.—iVe/jaiia Jiipen.* (After Sars.) /(, heart; i, intestine; o, ovar^; a, aflductor of earapace ; h, brain ; r, rostrum. pound stalked eyes. The few species are all marine and belong to the genus Xehalia. N. hipes * (fig. 432). Legion II. Thoracostraca {PodojMliahnia). The names given this division have reference, first, to the fact that the head and more or fewer of the thoracic segments are united into an immovable part, covered by a firm carapace; second, that the compound eyes (except in C'umacea) are placed at the ends of movable eye stalks, a condition which has jDOSsibly arisen from tlie inflexibility of the anterior part of the body. The first five appendages are always two jjairs of antennas, a pair of majidibles, and two pairs of maxillffi. The remaining jiairs vary greatly in character and from one to three may be modified into maxillipeds, while the abdominal somites except the last (felsov) usually bear appendages, at least in the female. There is usually a metamor- phosis in development in which a naiTplius-stage may appear, most frequently in the lower forms (schizopods), but even in the deca- pods [Peneiis).. 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 Hertwig, Richard, 1850-1937; Kingsle
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1902
