"Homasterope, new genus
TYPE-SPECIES—Asterope curta Skogsberg, 1920: 498, figs. 93, 94.
ETYMOLOGY—The prefix "Horn" from the Greek "homos" [= same, uniform, like, similar] refers to the similarity of the sensory bristles on the 5th joints of the 1st antennae on males and females. Gender: feminine.
This new genus contains four species: H. curta (Skogsberg, 1920); H. glacialis (Miiller, 1908); H. maccaini, new species; and H. micro, new species. Poulsen (1965:362) included Asterope curta Skogsberg in his new genus Parasterope. In the diagnosis of Parasterope, Poulsen (1965:362) states concerning the sensory bristle on the 5th joint of the first antenna: "The bristle has in the female only the six long terminal filaments; in the males is along most of the stem a dense clothing of long, hair-like filaments, and about 6 stouter filaments are placed near the tip." Poulsen may have overlooked Skogsberg's statement (1920:501) that the sensory bristle of the male A. curta is of the same type as that of the female. A female-type sensory bristle is also present on the male A. glacialis (Müller, 1908, pi. 8: fig. 15) and on the male H. maccaini described herein. Because these three species differ in this important character from other species which have been referred to genera of Cylindroleberidinae, it is considered expedient to establish a new genus to include them.
DIAGNOSIS OF GENUS—This genus is based on the presence of a female-type sensory bristle on the fifth joint of the male 1st antenna. The females of the new genus have fewer than 6 bristles along the dorsal margin of the 3rd joint of the 1st antennae, which is encountered rarely among other genera in the subfamily.
Carapace: Male and female carapace short and less than 2 mm long in four known species. Posterior infold without processes between list and posterior edge of valve; posterior list with numerous transparent bristles; number of bristles between list and posterior edge of valve varies considerably in different species.
First antenna: Dorsal margin of 3rd joint with 5 bristles on female and 4 or 5 on male; sensory bristle on 5th joint with only 6 terminal filaments on both male and female; d-bristle missing.
Second antenna: Protopodite with small medial bristle. Endopodite of female 3-jointed with terminal filament longer than stem; endopodite of male 3-jointed: 1st joint bare; 2nd joint with 3 distal ventral bristles; 3rd joint reflexed with fairly long proximal bristle and ridges along tip. Exopodite: no basal spines except (or lateral spine on 9th joint; 9th joint with 3 bristles.
Mandible: Ventral branch of coxale endite with 2 or 3 stout teeth at tip (known only for H. maccaini). Basale endite with glandular peg, 4 terminal bristles, 1 or 2 dwarf bristles and 3 or 4 triaenid bristles; latter bristles with only 2 to 5 pairs of marginal spines excluding terminal pair. Basale: dorsal margin of female without midbristles; dorsal margin of male bare or with 1 midbristle; medial surface of female with clusters of spines. Exopodite with hirsute tip and 2 short spinous bristles reaching proximal end of 1st endopodite joint. Endopodite: 2nd joint with long lateral bristle between b- and c-bristles on dorsal margin and relatively few (4-7) medial cleaning bristles.
Maxilla and fifth limb: Similar to those of Parasterope.
Sixth limb: Anterior margin with 1 upper bristle and 1 or 2 lower bristles (2 lower bristles present on at least 1 limb); anteroventral corner with 2 or 3 bristles; posteroventral margin with 16 to 20 bristles.
Seventh limb: Each limb with 14 to 18 bristles; terminus with 2 opposing combs, each with 5 to 9 teeth.
Furca: Each lamella with 7 to 9 claws.
Posterior: Posterior spinous with rounded dorsum.
Lateral eyes: Lateral eyes of female and male well developed, with about 20 ommatidia; eyes of male larger than those of female.
Rod-shaped organ: Organ 1-jointed with rounded tip.
COMPARISONS—This new genus Homasterope is closely related to the genus Parasterope and is separated from it because of having a female-type sensory bristle on the 1st antenna of the male. Females may be identified by having fewer than the 6 bristles present on the dorsal margin of the 1st antenna. An exception is Parasterope pollex Kornicker, 1967, which also only has 4 or 5 bristles on the 3rd joint of the 1st antenna. Females of that species can be separated from those of Homasterope by having a thumblike dorsum.
DISTRIBUTION—Species of the genus Homasterope have been collected only in the study area. The northernmost latitude specimens have been collected is 43°30'S off the Pacific Coast of Chile. The southernmost locality is at Gauss Station, 65°S, 90°E. The known depth range is 6 to 385 m." (Kornicker, p.524-255)
