FIGURES 1–12 in Halecium arcticum (Cnidaria: Hydrozoa), a new species of hydroid from Spitsbergen

FIGURES 1–12. Halecium arcticum sp. nov, all after preserved material from Spitsbergen. (1) Colony silhouettes, the left one is polysiphonic, the right one monosiphonic, scale bar 5 mm. (2) Typical branching pattern, scale bar 0.2 mm. (3) Terminal region of a branch with two hydrothecae, note presence of a pseudodiaphragm below diaphragm and the short, quadrangular segments, scale bar 0.1 mm. (4) Primary and secondary hydrothecae, scale bar 0.1 mm. (5) Female gonotheca in frontal view, scale bar 0.5 mm. (6) Same as (5), in side view. (7–9) Female gonothecae, note variation, same scale as (5). (10) Distal end of female gonotheca with characteristic horns flanking the opening, scale bar 0.2 mm. (11) Rare, mature, female gonotheca lacking distal horns; same scale as 10. (12) Mature male gonotheca seen from broad side, with sperm mass, scale bar 0.2 mm. (13) Immature male gonotheca, same scale as (12).