S. Mahunka szerk.: Folia Entomologica Hungarica 57. (Budapest, 1996)

triangular. The main part of its dorsal wall is clearly transparent. This transparent part is surrounded by a dark, strongly sclerotized belt with two wide proximal lobes. The other dorsal and lateral parts of the bursa copulatrix are wrinkled, leather-like, opaque. The dark, sclerotized belt is a support for the insertion of a well-developed (mostly dorsoventral) musculature, and may be homologous with the triangular loop of sclerotized projections occurring in the same position in FEIG of Sialis (Sziráki 1996). This possible homology between the bursal structure of Ithonidae (Neuroptera) and Sialidae (Megaloptera) also is supported by the fact that the dorsal surface within the sclerotized loop differs from that out of this structure in the case of the genus Sialis as well. The ventral membrane of bursa copulatrix (which is connected to the edges of 8th sternite) caudally has a pair of well-sclerotized conic cups. In normal position these cups cover the corresponding distal projections of the 8th sternite. From the antero-ventral part of bursa copulatrix a pair of narrow, but well-chitinized ducts are issued ending in two elongated bladder-like structures. As their position and shape are exactly the same as those of the paired spermathecae of Osmylidae, I regard these also in the family Ithonidae as spermathecae. Basal part of receptaculum seminis displays a strong sclerotization, which may be a part of a pumping structure. When the abdomen of the examined specimen was boiled in lactic acid (instead of potassium hydroxide), a non-chitinized, opaque layer was visible, which covered the spermathecae and their ducts as well. If the clearing was carried out with 5% KOH for 2 minutes (instead of the usual 10% KOH, 5 min. duration), the above mentioned layer was partly destroyed, while as a result of the usual KOH treatment it disappeared (Fig. 1). The two spermathecal ducts merge just at their base. Proximal part of the ductus seminalis is incorporated into the bursa copulatrix. Before the caudal end of this incorporated part a very strong sclerotization begins, which consists of two lateral pieces, while in the sagittal plane this section of the fertilization canal is membraneous. This kind of heavily sclerotized ductus seminalis presumably takes part in a pumping mechanism. Similar structures are known also in the families Polystoechotidae and Psychopsidae, in the coniopterygid subfamilies Aleuropteryginae and Brucheiserinae (Sziráki 1996), and in a recently described genus (namely: Adelphohemerobius) within the family Hemerobiidae (Oswald 1994a). Distal part of the ductus seminalis, as well as the median oviductus moderately sclerotized. Postbursal accessory gland minute, and opens into the vagina dorsally. Apart from the strong, split sclerotization being in the ductus seminalis of Ithonidae, the above detailed structure of the female internal genitalia agrees well with the "FEIG Type I" (cf. Sziráki 1996), which is known in the families Dilaridae, Osmylidae, Sisyridae and Nevrorthidae. As the mentioned split sclerotized structure of the ductus seminalis occurs not only in the ithonids, but also in other neuropterous families belonging to different evolutionary lines, I regard this feature as a part of the ground plan of Neuroptera. A survey of FEIG and the larval antennae of the neuropterous families Similarities being in the structure of FEIG and in the features of larval antennae in many cases well correspond to the superfamily ranking used by New (1991) — and which is similar to that of Withycombe (1925).