Licornia ferox Busk, 1852a

(Figs 2A, 3 A–B; Table 1)

Scrupocellaria ferox Busk, 1852a: p. 370; Busk, 1852b: p. 25, pl. 22, figs 1, 2, 5. Harmer, 1926: p. 367, pl. 25, figs 1–6. Licornia ferox: Vieira et al., 2013: p. 1916, fig. 4c–d.

Material examined. TAB 12 from Stn JP 01-1.

Description. Colony erect, flexible, bushy, dichotomously branched (Fig. 3A), with internodes comprising 10–12 zooids. Autozooids at slight angle to each other, biserial and triserial at the bifurcation, subrectangular with rounded distal corners. Opesia oval, narrower proximally, c. three-quarters of zooid length. Oral spine bases 4, tiny, arranged around distal rim of zooid. Scutum absent. Small lateral avicularium (Fig. 3B) present, with acute rostrum, located at outer distal corner of each zooid. Gymnocyst very short proximally or concealed by vibracular chamber and avicularium. Cryptocyst extremely narrow, smooth. Frontal avicularium with triangular rostrum, located proximally on gymnocyst in almost all zooids. Axial vibraculum single, prominent in frontal view, elongate with thin seta. Rhizoids tubular, with some retroussé hooks. Ovicell not observed.

Remarks. Vieira et al. (2013) resurrected the genus Licornia, distinguishing it from Scrupocellaria van Beneden, 1845 on the basis of several characters, the most obvious being that Scrupocellaria has a straight vibracular groove (slightly curved in Licornia), two axial vibracula (one in Licornia) and an ectooecium with only a single small fenestra (multiporous in Licornia).

Among Licornia species, L. ferox most resembles L. cyclostoma (Busk, 1852a), L. longispinosa (Harmer, 1926) and L. jolloisii (Audouin, 1826) . However, L. ferox is distinguished by the absence of frontal scuta, while in L. cyclostoma and L. longispinosa scuta are present. The scuta of L. cyclostoma are present only in ovicelled zooids, while L. longispinosa has oval scuta in all zooids as well as very long distal spines. Licornia jolloisii is characterized by the presence of a stout spine-like scutum with a sharp point (Vieira et al. 2013).

Distribution. Licornia ferox was originally collected by the expedition of HMS Rattlesnake in the Louisiade Archipelago and Papua New Guinea (Busk, 1852a), and also during the Siboga Expedition in Java, Indonesia (Harmer 1926).