. Fresh-water biology. Freshwater biology. 7IO FRESH-WATER BIOLOGY 92 (87) No hepatic ceca; setae 0-0-0-s 1-1-3 93 93 (94) Convolution of intestine in middle of body. Valves crested, with strong tooth on crest. . Drepanothrix Sars 1861. Sole species. ... Drepanothrix dentata (Euren) 1861. Valves reticulated; dorsal margin arched, crested, with conspicuous, short, backward- pointing tooth about middle. Antennules broad, flat, twisted, though not so much as in Streblocerus; post-abdomen compressed but not extended into a thin edge; almost quadrate as seen from side. Margin with 2 rows of small s
. Fresh-water biology. Freshwater biology. 7IO FRESH-WATER BIOLOGY 92 (87) No hepatic ceca; setae 0-0-0-s 1-1-3 93 93 (94) Convolution of intestine in middle of body. Valves crested, with strong tooth on crest. . Drepanothrix Sars 1861. Sole species. ... Drepanothrix dentata (Euren) 1861. Valves reticulated; dorsal margin arched, crested, with conspicuous, short, backward- pointing tooth about middle. Antennules broad, flat, twisted, though not so much as in Streblocerus; post-abdomen compressed but not extended into a thin edge; almost quadrate as seen from side. Margin with 2 rows of small spines, about 20, and with several rows of hairs besides scattered groups; apex truncate, emarginate, with anus in depression. Claws short, broad, crescentic, smooth, or denticulate; 5 pairs of feet. $ much like young 9 ; hook on first foot; post-abdomen without spines; vasa deferentia open in front of claws. Color whitish to yellowish; opaque or transparent. Length, 9»ca. mm.; ^ , ca. mm. Not commonly collected though widely distributed and probably not very rare in shallow waters of lakes, on bottom or among weeds. Maine, Michigan, Wisconsin, Minnesota, 94 (93) Sole species. Fig. 1104. Drepanothrix dentata. Convolution of intestine in hind part of body and in post-abdomen. No dorsal tooth. . Acantholeheris Lilljeborg 1853. Acantholeberis curvirostris (0. F. Miiller) 1776. Form in general angu- lar-oval, not compressed, without crest. Posterior margin of valves roimded over into ventral, both fringed with long, close- set, plumose setae. La- brum with long, slender, conical process. Anten- nules large, flat, some^vhat curved, expanded toward apex. Post-abdomen large, moderately broad, not compressed or divided, hairy, with 20 or more small dorsal spines in each row; anus terminal. Claws short, stout, broad, curved, denticulate, and with 2 . small basal spines set side by side. Six pairs of feet. Intestine without ceca, convoluted, the loops lying in great pa
Size: 2462px × 1015px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
