Milnesium

Key to the determination of recent species of the genus Milnesium. (adult females)

1. Claws of all legs without main branches.................................. Milnesium dujiangensis

­ Claws of all legs with main branches........................................................................... 2

2. Cuticle reticulated 1...................................................................................................... 3

­ Cuticle smooth............................................................................................................. 4

3. With gibbosities on dorsal surface and eyespots. Inner claws of all legs with basal spurs ..................................................................................................... Milnesium reticulatum

­ Without gibbosities and eyespots. Claws of all legs without basal spurs....................... ...................................................................................................... Milnesium katarzynae

4. Buccal tube wide and short, with its diameter decreasing to the caudal end. Its diameter in the region of mouth opening exceed 30 µm ..................... Milnesium eurystomum

­ Buccal tube cylindrical, with diameter lesser then 30 µm............................................ 5

5. Without accessory points on main claw branches......................................................... 6

­ With accessory points on main claw branches.............................................................. 7

6. Outer claws without basal spurs; length ratio between complex base+secondary branch and basal spur of inner claws do not exceed 2.5................................................. .......................................................................................... Milnesium reductum sp. nov.

­ All claws with basal spurs; length ratio between complex base+seconfary branch and basal spur not lesser then 3.......................................... Milnesium longiungue sp. nov.

7. Short claws; pt value for main claw branches in legs IV lesser then 40, pt value for complex base+secondary branch in legs IV lesser then 30 ...... Milnesium brachyungue

­ Longer claws; pt value for main claw branches in legs IV larger then 40; pt value for complex base+secondary branch in legs IV larger then 30........................................... 8

8. Longer, more subtile claws; pt value for main claw branches in legs IV larger then 60....................................................................................................................................... 9

­ Shorter, more massive claws; pt value for main claw branches in legs IV lesser then 60.................................................................................................................................... 10

9. Buccal tube length exceed 50 µm; length of the main claw branches in legs IV exceed 30 µm; with basal spurs on all claws ............................... Milnesium asiaticum sp. nov.

­ Buccal tube length not exceed 42 µm (usually lesser then 40 µm); length of the main claw branches in legs IV not exceed 30 µm; outer claws on legs I–III and both claws on hind legs lacks basal spur ........................................ Milnesium almatyense sp. nov.

10. Pt ss value more then 70 (70.7–75.9); with basal spurs on all claws................................................................................................................... Milnesium antarcticum sp. nov.

­ Pt ss value lesser then 70 (usually 63–66); basal spurs of outer claws could be reduced.................................................................................................................................... 11

11. Four peribuccal lamellae; pt ss value 61.98–64.37 (according to Pilato & Binda 1991);

1. This character is also noted in some populations of Milnesium tardigradum (Nelson & Horning 1979) but in my opinion this material should be reinvestigated to ascertain its taxonomic position.

in the complex base+secondary branch apical points are almost equal in size............... .............................................................................................. Milnesium tetralamellatum ­ Six peribuccal lamellae; pt ss value 62.7–67.7; in the complex base+secondary branch point a is distinctly smaller then point b................................... Milnesium tardigradum