. Bulletin - United States National Museum. Science. ISOFODS OF NORTH AMERICA. 61 short, being- only lono- the lirst abdominal ,seo-nient, and narrower, about one-third as wide as the sixth thoracic segment; it could easily be taken for one of the abdomitial segments. The lirst live seg-ments of the abdomen are short, distinct, and sub- equal in length; they are l)ut little wider than the seventh thoracic segment, but abruptly narrower than the sixlh thoracic segment. The sixth or terminal segment is triaugular in shape, with a])ex very acute. The uropoda extend to tln^ extremity of th
. Bulletin - United States National Museum. Science. ISOFODS OF NORTH AMERICA. 61 short, being- only lono- the lirst abdominal ,seo-nient, and narrower, about one-third as wide as the sixth thoracic segment; it could easily be taken for one of the abdomitial segments. The lirst live seg-ments of the abdomen are short, distinct, and sub- equal in length; they are l)ut little wider than the seventh thoracic segment, but abruptly narrower than the sixlh thoracic segment. The sixth or terminal segment is triaugular in shape, with a])ex very acute. The uropoda extend to tln^ extremity of the abdomen. The inner ])ranch is a little wider and a very littl(> longer than the outer branch. Both are narrow, elongate, with extremities obliquely trun- cate, the post-lateral angles being rounded. There are apparently only five paii-s of thoracic legs. The first pair are modified and opercular, and are composed of only two arti- cles. The seventh pair are wanting. The remaining live pairs are ambulatory. Deaci-lption of female.—Bod}" ovate, about twice as long as wide, 2 mm. :4 mm. Head smaller than in male, with the front produced in a lobe which is emarginate in the middle. Eyes small, round, composite, and situated at the post-lateral angles of the head. Antennte of both pairs as in male. The tirst segment of the thorax is short and narrow and almost inconspicuous, appearing as a small lobe back of the head. The thorax becomes wider with the second thoracic seg- ment. The second and third segments are short and about equal in length. The fourth and fifth are verv long, many times longer than the '^'^ ^ cerina - "' "^ " . , (After Harger). Female. preceding segments and scarcely to be distin- guished, being somewhat fused dorsally. They are nearly su})equal. The sixth segment is about half as long as the preceding segment, and becomes gradually narrower from the anterior to the posterior extrem- ity. This segment is also som(nvhat fused
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