Figs. 16 – 17. 16 in A Description of the First Instar of Hoperius planatus Fall, 1927 (Coleoptera: Dytiscidae: Colymbetinae: Colymbetini), with Phylogenetic Implications Barman, E. H. Michat, M. C. Alarie, Y. Wolfe, G. W. The Coleopterists Bulletin 2007 61 3 351 397 3DK8 1076114 Thomson 1859 [720,807,630,652] Insecta Haliplidae Brychius Animalia Coleoptera 16 Arthropoda genus    1. Prosternal process constricted at the level of procoxae, gradually widening posteriorly to apex making the anterior lobe distinctly wedge-shaped ( Fig. 6c); last abdominal segment with blunt point; hood lobe of aedeagus truncated, a deep distinct channel separating it from the median lobe ( Fig. 11c)................................................  Brychius pacificusCarr  – Prosternal process constricted at the level of procoxae, nearly parallel to apex ( Figs. 6a, b); last abdominal segment with long sharp point; hood lobe of aedeagus rounded, not distinctly separated from the median lobe.......... 2   2. Humeral margin of elytron with serrations; large specimens, total length 3.7– 4.4 mm; aedeagus with apex of median lobe long and slender, narrowing at the tip; hood lobe pointed ( Fig. 11b)..........  Brychius hungerfordiSpangler  – Humeral margin of elytron without serrations; total length 3.0– 3.8 mm; aedeagus with curvature of the median lobe not pronounced, apex rounded and the hood lobe small, laying almost against the median lobe ( Fig. 11a).................................................  Brychius horniiCrotch