is this a mistake?

[pmda]

In orberg's LLPSI he gives two explanations of Cyclops, one singular plural: but they're they same 3rd declension masculine noun. Why would he provide a singular explanation : Cyclops, -opis (m) and a plural definition: Cyclopes, -um (m)

?

[Alatius]

Perhaps he wants to make a distinction between an individual "cyclop" and the name of the people (or species if you want), namely "the cyclops". That's the only explanation I can think of.

[pmda]

Alatius, thanks.