Figure 1 in Redescription of the leptothecate hydroid Halecium macrocephalum Allman, 1877 (Cnidaria: Hydrozoa)

Figure 1. Distinguishing morphological characteristics of the leptothecate hydroid Halecium macrocephalum Allman, 1877. The colony is densely branched with a thick, strongly polysiphonic hydrocaulus (A; scale bar 10 mm). Notably, many hydrothecae are steeply sloped at an approximately 45◦ angle (B; scale bar 500 µm). The kidney-shaped nature of the female gonotheca (C; scale bar 1 mm). The characteristic sigmoidal and elongated shape of the male gonothecae form the basis for this redescription (D; scale bar 1 mm), a shape that differs significantly from that figured for the holotype by Allman (1877).