. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). TYPE VHV8TACEA. 419 all the members of the class, and it is only in the Civrliipedia that a Hecoutl definite larval form can be diHtinj^'uished, the Oypris-larva, to which attention has already been called (p. M99). In the Malacostraca the occurrence of a free-swinuninfj; Naiipliiis is the exception rather than the rule, and indeed larval forms are practically wanting in some groups, such as the Leptostraca and Arthrostraca, and iu certain species or families of other
. A textbook of invertebrate morphology [microform]. Invertebrates; Morphology (Animals); Invertébrés; Morphologie (Animaux). TYPE VHV8TACEA. 419 all the members of the class, and it is only in the Civrliipedia that a Hecoutl definite larval form can be diHtinj^'uished, the Oypris-larva, to which attention has already been called (p. M99). In the Malacostraca the occurrence of a free-swinuninfj; Naiipliiis is the exception rather than the rule, and indeed larval forms are practically wanting in some groups, such as the Leptostraca and Arthrostraca, and iu certain species or families of other groups ( My8id(Vy Camharvs). In the genus Penceits among the Decapods, and iu Ei(plutusia among the Schizopods, a typical free-swimming Nauplius occurs, and in Lvjcifer the embryo leaves the egg in the form of the Meta- nauplius. In the majority of forms these stages are passed over while the embryo is still within the egg-shell, and it hatches only when it has acquired a greater degree of develop- ment. In such forms as Pfenrews, Ewphmma^ and Lucifer the Metanauplius stages pass into what is termed the Protozoea (Fig. 192, A) a stage also passed over within the egg by the mx«. Fig. 193.â^, PaoTOZofiA op Zt/ct/fer (after Brooks); B, ZofiiA OF Palamonetes (after Faxon). At^ = autenuule. m = muDdible. At^ = antenna. 7nx\ mx'^ = miixillse. c = cerebral gaDglion. mp\ mp^ = maxilllpeds. E = compound eye. oc = simple eye. h = heuit. r = rostrum. 8 = stomach. majority of Malacostracaus, though occurring as the first larval stage of some Stomatopods. It is characterized by the development of two maxillae and the two or three anterior :;!' r ii it III m i ' >â ! ii f ' 1 ill >⢠1 iliH â I' ill. 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 McMurrich, J. Playfair (James Playfair), 1859-1939.
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1894
