New species from the nivicola group of Hypogastrura Bourlet, 1839 (Collembola, Poduromorpha, Hypogastruridae) from Canada Author Cipola, Nikolas Gioia text Zootaxa 2020 2020-06-02 4786 2 199 220 journal article 10.11646/zootaxa.4786.2.3 1175-5326 3874679 A377ED06-9734-42BD-8129-6199C3048BD2 Hypogastrura nivicola group Diagnosis. Ant IV with simple apical bulb and rod-like sens; head with 1+1 or 2+2 v-chaetae (v1, v2); PAO about as large as an eye and with 4 lobes; body with smooth and/or unilaterally serrated chaetae; abdominal segments and tibiotarsal proximal whorl rarely with elongated chaetae apically clavate; clavate tenent hairs; anal sacs everted or not; unguiculus internally with broad proximal lamella (ai); collophore with 4 or more chaetae; tenaculum with 4 teeth; dens dorsally with tubercles, spines present generally in winter form and rarely in summer form; mucro boatshaped with or without dorsal subapical tooth (adapted from Yosii 1960 ; Fjellberg 1985 ; Christiansen & Bellinger 1998 ; Thibaud et al . 2004 ; Skarżyński 2009 , 2019 ).