Sicyonis Hertwig, 1882

Gusmão, Luciana C. & Rodríguez, Estefanía, 2021, Deep-Sea Anemones (Cnidaria: Anthozoa: Actiniaria) From The South Atlantic, Bulletin of the American Museum of Natural History 2021 (444), pp. 1-73 : 13

Genus Sicyonis Hertwig, 1882

DIAGNOSIS (modified from Carlgren, 1949; modifications in bold): Actinostolidae with welldeveloped pedal disc and rather thick column; tentacles covered by distal column. Mesogleal marginal sphincter musculature weak or fairly well developed. Tentacles short, inner ones considerably stronger than outer ones and about half as numerous as mesenteries; aboral base of tentacles often thickened. Longitudinal muscles of tentacles and radial muscles of oral disc mesogleal. Two broad siphonoglyphs. Often 16 pairs of perfect mesenteries with a variable number of pairs with one perfect and one imperfect mesentery. Arrangement of mesenteries not as regular as in Actinostola , but with strong tendency to unequal development of mesenteries in a pair. Retractors weak, diffuse, and parietobasilar and basilar musculatures well developed. Mesenteries differentiated into stronger, fertile mesenteries with well-developed filaments and into weaker fertile mesenteries without filaments proximally h do not reach the distalmost part column. Cnidom: spirocysts, basitrichs, p -mastigophores A.

TYPE SPECIES: Sicyonis crassa Hertwig, 1882 , by original designation.

VALID SPECIES: Sicyonis careyi Eash-Loucks and Fautin, 2012 ; S. crassa ; S. erythrocephala ( Pax, 1922) ; S. gossei ( Stephenson, 1918b) ; S. haemisphaerica Carlgren, 1934 ; S. heliodiscus Sanamyan et al., 2015 ; S. ingolfi Carlgren, 1921 ; S. obesa ( Carlgren, 1934) ; S. sumatriensis Carl- gren, 1928a; S. tuberculata Carlgren, 1921 ; S. tubulifera ( Hertwig, 1882) ; S. variabilis Carlgren, 1921 ( Fautin, 2016) .