Celsinotum Frey, 1991

Parthenogenetic female short description. Body round, with convex posterior margin; head without keel; valves with well-defined keel (Fig. 8 I). Sculpture of valves as longitudinal lines. Posteroventral angle of valves without denticles. Rostrum short, truncated. Three main head pores with narrow connection between them, lateral head pores minute (Fig. 8 J). Labral keel of moderate width, with rounded apex, without clusters of setulae on posterior margin.

Postabdomen long and narrow, narrowing distally in postanal portion, with broadly rounded distal angle; length about 3.5 height (Fig. 8 K). Preanal and postanal angles well defined. Postanal denticles small, their length not exceed width of postabdominal claw base. Postanal lateral groups of setulae of moderate length; in distalmost groups, length of setulae exceed the width of base of postabdominal claw. Postabdominal claw long, weakly curved, with long straight basal spine.

Antennule without lateral aesthetasc; two terminal aesthetascs very long, much longer than others. Antennal seta without basal peg. Antenna with thin seta on basal segment of endopodite (Fig. 8 L). Spine on basal segment of exopodite about 2/3 length of middle segment. Spines on apical segments about 1/3 length of apical segments. IDL of limb I with three setae; seta 1 minute, rudimentary; setae 2–3 thin, armed with spinulae.

Single species, Celsinotum macronyx (Daday, 1898) (Fig. 8 I–L). Length of adult female 0.41–0.52 mm. Rare species, found in lakes. Littoral species, associated with vegetation. Indo-Malaysian species, distributed in India, Sri Lanka, Indochina, South China and Indonesia (Sinev & Kotov, 2012). For detailed description see Sinev & Kotov (2012).

Taxonomic notes. Externally, C. macronyx can be confused with Notoalona pseudomacronyx, which have similar outline of body and similar shape of postandomen, but it can be easily separated by the morphology of postabdominal claw; in N. pseudomacronyx length of basal spine is less than 1/3 length of claw, and in C. macronyx it is close to half-length of claw. Drawings of C. macronyx in Maiphae (2014) belong to N. pseudomacronyx instead.