. Fresh-water biology. Freshwater biology. Fig. MM. ' 1131. Alona intermedia. 166(151) With oblique Striae Alonella karua Turn to the key at the number indicated where the species named is discussed. 232 167 (137) Rostrum broad, semicircular Graptoleberis Sars 1863. Sole species Graptoleberis iestudinaria (Fischer) 1848. Posterior margin with 2 strong teeth at infero-posteal angle; valves and head with conspicuous reticulation. Head large; fornix very broad, forming a semicircular rostrum, covering anteimules and extend- ing down as far as ventral margin of valves. Post-abdomen bent at the
. Fresh-water biology. Freshwater biology. Fig. MM. ' 1131. Alona intermedia. 166(151) With oblique Striae Alonella karua Turn to the key at the number indicated where the species named is discussed. 232 167 (137) Rostrum broad, semicircular Graptoleberis Sars 1863. Sole species Graptoleberis iestudinaria (Fischer) 1848. Posterior margin with 2 strong teeth at infero-posteal angle; valves and head with conspicuous reticulation. Head large; fornix very broad, forming a semicircular rostrum, covering anteimules and extend- ing down as far as ventral margin of valves. Post-abdomen bent at the sharp pre-anal angle; tapered toward claws, so that form is nearly triangular; marginal spines small; lateral fascicles minute, some- times wanting. Claws small, with i mi- nute basal spine, sometimes wanting (var. inermis Birge); $ with long, slender post- abdomen, without spines; vas deferens opens on ventral side; claws very minute; hook of first foot slender. Length, 9, mm.; $, mm. or. MM. 1 1 Fig. 1132. Graptoleberis iestudinaria. Color gray to yellow-white; sometimes opaque less. Common among weeds or on bottom of pools and margin of lakes. 168 (136) Rostrum considerably exceeding antennules. 169 169 (170) Post-abdomen with marginal denticles only. Alonella. Turn to the key at the numbers indicated where two species are discussed. 240, 241 170 (169) Two to four marginal denticles; long series of lateral denticles. Rostrum very long, recurved. . Rhynchotalona Norman 1903. Sole species Rhynchotalona falcata (Sars) 1861. General form of body like Alona. Ros- trum very long, slender, and recurved under the head. Post-abdomen stout, thick, bent at anus, truncate at apex; with_ about four rather stout marginal denticles near apex, and a lateral series, continued nearly to anus, of very fine spinules in an unbroken row. Intestine with cecum. $ (European) with long rostrum, bilobed at apex; post-abdomen tapering and armed with hairs only; ordi- nary hook on first
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
