A new species of planorbid mollusc,
Plesiophysa dolichomastix
(Greek dolichos = long, mastix = flagellum), collected from Lagoa da Pedra,
municipality of Santa Rosa, state of Goiás, Brazil (15°01'S, 47°13'W)
is described. It is indistinguishable by the shell characters from the five
congeneric species described so far:
P. striata
(Orbigny, 1841),
P. granulata
("Shuttleworth" Sowerby, 1873),
P. guadeloupensis
("Fischer" Mazé, 1883),
P. ornata
(Haas, 1938) and
P. hubendicki
Richards & Ferguson, 1962. It differs from the anatomically studied
species in the following characters: about 50 ovotestis diverticula, against
12 in granulata, 100 in ornata, unstated in hubendicki; and length of flagella
- about as long as the penial complex -, against about 1/3 to 1/6 in the
other three.
