Ingolfiella cottarellii new species from a freshwater pool in a cave on the island of
Tavolara (NE Sardinia), the first true cave dwelling species of this genus, is described.
This species, without ocular lobes, oostegites and $ pleopods, $ with only pleopod 1, is
very similar to /. catalanensis and /. thibaudi, strongly differing only in the shape of
gnathopods 2 carpus and uropods 1 and 2. A well characterized group of species
{Tyrrhenidiella n.subg.) is therefore recognized.
An examination of the new species' relationships with, and its taxonomic position
among, the different groups in which the 27 known species are distinguishable, led to
a critical discussion of the main diagnostic characters, to a study of more new material
regarding some species (a redescription of some characters of /. ruffoi is also given),
and to proposing a new arrangement of subgenera.The genus Ingolfiella Hansen, 1903
is therefore divided into: Ingolfiella Hansen, 1903 (3 species, plus one assigned
dubitatively); Hansenliella Stock, 1981 (3 species); Tethydiella n.subg. (6 species);
Antilleella n.subg. (5 species); Gevgeliella S. Karaman, 1959 (2 species); Balcanella S.
Karaman, 1933 (3 species, plus one assigned dubitatively); Tyrrhenidiella n. subg. (3
species). All these subgenera are described and discussed, and a key is given.
A cladistic analysis of the 12 main characters for the 7 subgenera is attempted.
The resulting cladograms are also discussed, leading to the conclusion to divide the
genus Ingolfiella into two groups of subgenera: the first, with ocular lobes developed
and connected to sea water, is more primitive; the second, with ocular lobes reduced or
absent and connected to continental fresh or anchihaline water, includes intermediate
or decidedly more evolved subgenera.