Specimens of
Hedylopsis spiculifera (Kowalevsky, 1901) from sands of the Mediterranean Sea and the type specimens of
H. suecica Odhner, 1937, as well as live specimens from its type locality in the Skagerrak, were studied. The anatomy of the reproductive system and the central nervous system of both forms - considered conspecific by several authors - is described and discussed. Contrary to the original description,
H. suecica has the same reproductive system as
H. spiculifera, showing an arrangement of the gonoduct unique among acochlidians. The animals are sequential hermaphrodites and have in the female phase an ampulla and not a bursa copulatrix. The ‘albumin’ gland appears as a blind sac set off from the gonoduct, hence its cavity is probably not traversed by the eggs. Since neither a receptaculum seminis nor a bursa copulatrix was found, it is concluded that sperm are transferred by injection using the penial spine as a hypodermic needle. The specimens from the Skagerrak also have spicules in the head region, as described for
H. spiculifera. Therefore
H. suecica is considered a synonym of
H. spiculifera.
