Isodictya delicata var. megachela Burton, 1934

Isodictya delicata var. megachela Burton, 1934b: 20.

The variety was described by Burton from Seymour Island, Grahamland, Antarctica, 64.3333°S 56.6333°W, depth 150 m (holotype presumably in the Stockholm Museum, with additional type material BMNH 1933.3.17.7, and three slides). The variety was erected on the basis of differences with the typical variety described by Thiele (1905: 435 as Desmacidon delicata, from Admirality Sound, Chile, 54.31°S 69.5°W, depth 10 m, holotype ZMB 3289) in shape (flabellate vs. finger-shaped in the typical variety) and spicule sizes (chelae 70 µm vs. 20 µm in the typical variety). According to Ríos (2006) and Ríos et al. (2020), there are also sigmas in the var. megachela, not reported in the typical variety. Since both varieties are of sympatric occurrence in nearby Antarctic localities, infraspecific status is not warranted in this case. Koltun (1964: 41) suggested the varieties were subspecies, but the argument of sympatry applies a fortiori for species level. The differences appear sufficiently large. I propose to elevate the variety to a distinct species Isodictya megachela Burton, 1934b.