. Fresh-water biology. Freshwater biology. A large mite, to mm. long, the gravid female often very large, reaching a length of even 6 mm., living in fresh-water mussels and laying eggs in masses between the gills. Honey- yellow in color, more or less distinctly finely vermicuJate with white lines. One North American species, generally distributed. Fig. 1348. Najadicola ingens (Koenike). Epimeral field and genital area, male. X 23. tAfter Koenike.) Inner side, pal- pus, male. X80. (After Wolcott.) 60 (59) Posterior margin of ep. IV straight; genital area at the posterior end of the body
. Fresh-water biology. Freshwater biology. A large mite, to mm. long, the gravid female often very large, reaching a length of even 6 mm., living in fresh-water mussels and laying eggs in masses between the gills. Honey- yellow in color, more or less distinctly finely vermicuJate with white lines. One North American species, generally distributed. Fig. 1348. Najadicola ingens (Koenike). Epimeral field and genital area, male. X 23. tAfter Koenike.) Inner side, pal- pus, male. X80. (After Wolcott.) 60 (59) Posterior margin of ep. IV straight; genital area at the posterior end of the body, genital plates not elongated transversely. (Parasitic species) Unionicola Haldeman Varying from small to large in size, Some are active, free-swimming mites with long legs, with swimming-hairs, and leg I frequently with movable, dagger- like spines. Others are mussel para- sites, with shorter legs and no swimming-hairs, leg IV in some cases being characteristically modified in the male sex. In both types strong spines adjacent to the genital opening serve together as an ovipositor. Cer- tain free-swimming forms are regularly pelagic and very transparent; the para- sitic forms are dull-colored. Species numerous and widely distributed, many of them very abundant, especially the parasitic forms. The latter are usually mussel parasites though one species has been recorded from a South American univalve. Fig. 1349. Unionicola crassipes (Mviller), a common and widely-distributed, free- swimming species, common to North America and Europe. Ventral surface, female. X 22. Palpus, outer side, female. X 63. (Modified from Piersig.) 61 (54) Posterior margin of ep. IV with a prominent acute angle. ... 62. 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 Ward, Henry Baldwin, 1865-1945;
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
