. Bulletin - United States National Museum. Science. Fig. 594.—Argeia itgettensis. First tory from specimens kol'nd ox: ((, Nectocrangon dentata from Afognak Bay, Afognak Island, x 11.;. h, NECTocRAXfiON crassa from off Cape Xewenham. Alaska. X 91 lai't'c luiinhcr of these t'onns, the eonchision must l)e iiiiiiiit:iinefl tliat these thoracic processes, well developed in th(> yoiiiio- foiuale. ol" \arv- ino- size and shape and sometimes so i-educed as to be practically absent in the adult female, have no specific value whatever, (xiard and Bon- nier have described t
. Bulletin - United States National Museum. Science. Fig. 594.—Argeia itgettensis. First tory from specimens kol'nd ox: ((, Nectocrangon dentata from Afognak Bay, Afognak Island, x 11.;. h, NECTocRAXfiON crassa from off Cape Xewenham. Alaska. X 91 lai't'c luiinhcr of these t'onns, the eonchision must l)e iiiiiiiit:iinefl tliat these thoracic processes, well developed in th(> yoiiiio- foiuale. ol" \arv- ino- size and shape and sometimes so i-educed as to be practically absent in the adult female, have no specific value whatever, (xiard and Bon- nier have described their function as organs of hxation, which seems a reasonable conclusion aiul one capable of explaining- why so much variation occurs in this respect with each individual parasite. Body of adult female some- what asymmetrical. Length, 14 mm.; width, 11 mm. Head wider than long-, 2 mm. : 3i mm., somewhat bilol)ed, with a narrow frontal border, the an- terior margin of which is slightly arched or rounded. The frontal boi'der projects at the side in a small angular lol)e. Eyes absent. The lirst pair of antennic are composed of two articles—a large basal article and a small terminal one. The second pair are composed of four articles. Both are small and not conspicuous on tlie dorsal side. All seven segments of the thorax are distinct. Ovarian l)osses are present on the first four segments, where they occupy the sub-lateral portion of the anterior part of the lateral margin. The epimera are narrow plates lateral to the ovarian bosses on the anterior part of the segments. The epimera also occupy the anterior part of the lateral margin of the last three segments, but the ovarian bosses are not present on these seg- ments. The posterior lobes on all the segments are large and irregular in outline, and more or less produced in narrow, some- what elongated processes, these processes being usually more developed on one side (the longer side) than on the other. All six segments of the a
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