Frontal and lateral avicularia. A, NHMUK 1888.4.16.200, Aspiscellaria frondis (Kirkpatrick, 1890) n. comb.; zooids without lateral avicularium. B–H, Zooids with sessile lateral avicularium (white and black arrows). B, NHMUK 2010.12.6.22, Cradoscrupocellaria odonoghuei Vieira, Spencer Jones & Winston, 2013; zooid with avicularium positioned at outer distal corner and directed obliquely distolaterally. C, NHMUK 1899.7.1.804, Scrupocaberea dongolensis (Waters 1908) n. comb.; zooid with avicularium positioned lateral to the opercular area and directed laterally. D–F, Rostrum of lateral avicularium. D, NHMUK 1936.12.30.146, Licornia gaspari (Thornely 1907); serrated lateral edge, straight at its tips. E, NHMUK 1968.1.18.110, Pomocellaria californica (Trask, 1857) n. comb.; smooth lateral edge, with curved tips. F, NHMUK 1899.7.1.804, Scrupocaberea dongolensis (Waters 1908) n. comb.; serrated lateral edge, strongly hooked. G–I, Dimorphic lateral and frontal avicularia (black arrows). G, NHMUK 1968.1.18.110, Pomocellaria californica (Trask, 1857) n. comb.; dimorphic lateral avicularium with triangular mandible. H, NHMUK 1998.9.29.6, Paralicornia sp.; dimorphic lateral avicularium with trifoliate mandible. I, NHMUK 1968.1.18.104, Licornia diegensis (Robertson, 1905) n. comb.; dimorphic frontal avicularium.