Genus Haasea Verhoeff, 1895

Xiphogona Cook, 1895: 3 (junior objective synonym)

Xiphigona Cook, 1895 —misspelled by Hoffman (1980: 130) (junior objective synonym)

Orobainosoma Verhoeff, 1897: 135 (junior objective synonym)

Rhopalogona Silvestri, 1898: 666 (junior objective synonym)

Deuterohaasea Verhoeff, 1898: 226 (junior objective synonym)

Orobainosoma (Brachybainosoma) Verhoeff, 1899: 128 (junior subjective synonym)

Heterohaasea Verhoeff, 1900: 362 (junior objective synonym)

Orobainosoma (Histrosoma) Strasser, 1973a: 419 (junior subjective synonym)

Type species: Craspedosoma flavescens Latzel, 1884 accepted as Haasea flavescens (Latzel, 1884) [by subsequent designation of Cook, 1895 in Cook & Collins (1895: 3)]

Diagnosis: A genus of Haaseidae with leg-pair 10 in males reduced in size compared to other walking legs (vs. robust in Hylebainosoma and Xylophageuma, an exception is H. nontronensis also with a reduced leg-pair 10 but this species differs from Haasea by numerous other gonopod and vulvar structures). Medial sternal process of the anterior gonopodal block bilobed distally (vs. not bilobed in Hylebainosoma and Xylophageuma). Angiocoxites sigmoid in lateral or mesal view (vs. mainly straight in Hylebainosoma and Xylophageuma, an exception is H. gulickai Tajovský, Mock & Papáč, 2014b with sigmoid angiocoxites, but this species differs from the other haaseids by the absence of ommatidia). Additional gonopodal processes mainly strongly curved posteriad in lateral or mesal view (vs. mainly straight in Hylebainosoma and Xylophageuma). Vulval bursae mesally completely merged.

Short description: Body in adults with 28 or 30 segments (including telson); 6.5–12 mm long.

COLORATION (Fig. 1). Variable, from poorly pigmented to light or darker brown. Most of species with yellowish-brown body.

HEAD (Fig. 2 A–F). Setose, frontal side flattened in males (Fig. 2A), slightly convex in females. Labrum with three medial teeth (Fig. 2B). Antennae elongated, slender, with dorsomedial and ventromedial lines of small papillae-like outgrowths (Fig. 2 D–F). Lateral to antennal sockets a group of similar papillae-like outgrowths present (Fig. 2C). Ommatidia brownish to black arranged in triangle, number from 9–16 (Fig. 2A).

BODY (Figs 1, 2 G–K). With lateral humps. Macrochaetae long and trichoid, present on large knobs. Posterior metazonal margins with small, triangular denticles. Collum and telson not modified.

LEG- PAIRS 1 AND 2 (Fig. 3E). In both sexes with tarsal combs; prefemora with several long and robust setae; femora and postfemora each with a group of several long and robust setae.

MALE SEXUAL CHARACTERS (Fig. 3 E–G). Leg-pair 2 with genital openings on coxae (Fig. 3E). Leg-pairs 3–7 enlarged. Distal half of tarsi 3–7 with ventral papillae (Fig. 3F). Leg-pair 10 significantly smaller than the other walking legs; with coxal sacks and with a robust, blunt coxal process (Fig. 3G). Leg-pair 11 with coxal sacks, no other modifications.

ANTERIOR GONOPODS (Fig. 3 A–C) Sternum (s) wide, with medial sternal process (msp, see Figs 25D and 34C) bilobed distally and anterior sternal lobe (asl) with several long setae, on both lateral sides. Long setae (1–3) also present on antero-paramedial and lateral parts of s. Angiocoxites (a) erected, sigmoid in lateral or mesal view, characterized by the presence of a deep, posterior and longitudinal furrow (f, see Figs 9B, 14C, 18C, E or 34D), extending from the base to the distal part, dividing superficially posterior portions of the angiocoxite into the mesal and lateral sides. Angiocoxites supplied with a few additional processes or extensions on both mesal and lateral sides. Mesal process (mp) always present, more or less well-developed, with or without additional teeth. Apart from mp, two more structures are always present on mesal side, viz., papillated cone (pc) and “ Opuntia -like” membranous lobe (ml) which might be a colpocoxite. Both structures more or less identical in all species. Laterally, two processes present, viz., anterior lateral process (alp) in only a few species and posterior lateral process (plp) in all species. The distal half of a bends anteriad. The most distal part (dp) complex, composed of structures with “hairs” or fimbriaelike outgrowths. In some species, this part has a mesodistal lobe (mdl) sometimes with fimbriae. Posteriorly, dp has a seminal opening (so) surrounded by minute fimbriae-like outgrowths. Below so, posterior lamella pl (sometimes also pl1, pl2) present, simple or bilobed. Inside a, (?) seminal canal (s c) is visible, starts from the basal half and opens distally in so. The most basal part of sc enlarged, in form of seminal chamber (sch) and ends with a cone structure (cs) covered with cilia or sensilla.

POSTERIOR GONOPODS (Fig. 3D). With reduced sternum (s, see Fig. 26J). Telopodites (t) well-developed, robust, with two podomeres, covered by long setae. Coxal processes (cp) present mesally, with two or three branches (ab, mb, pb).

LEG- PAIR 3 IN FEMALES (Fig. 3 H–J). With lateral sternal lobes (sl).

VULVAE (Fig. 3H). Operculum (o, see Figs 35G and 37A) membranous, with serrated edge and with a row of long setae. Bursae (b) merged mesally with bulbous structure, long setae and triangular denticles present on mesal and lateral parts. Postgenital plate (pgp) present, with lateral lobes and medial lobe. For vulvae details see Kurnik (1988: 234, taf I, 246–251).