Monstrillopsis planifrons sp. n., adult female holotype from the Canadian Arctic. A cephalic region, dorsal view B habitus, dorsal view, arrow shows three paired dorso-medial papilla-like processes on second pedigerous somite C urosome, ventral view, showing fifth legs, ovigerous spines not shown, only its insertion area D urosome, dorsal view E insertion of ovigerous spine on ventral surface of genital double-somite F terminal section of ovigerous spines G eggs along ovigerous spines. Scale bars: A, C, D 100 µm, B 500 µm, E–G 25 µm.