"Archasterope bulla, new species Figures 243, 244
HOLOTYPE—USNM 128964, gravid female, length 2.04. Valves and some appendages in alcohol, remaining appendages on slides.
TYPE-LOCALITY—Vema Cruise 17, station V-17-23.
ETYMOLOGY—The specific name is derived from the Latin "bulla" [ = bubble, knob, boss, seal, edict, ornament] and refers to the 4 processes or knobs on the posterior infold of each valve.
PARATYPES—USNM 128965, adult female; USNM 128966, juvenile (not dissected). Both paratypes from same sample as holotype.
ADDITIONAL SPECIMENS—USNM 1S8033, N-l male, length 1.78 mm, height 1.00 mm, from Eltanin Cruise 6, station 354.
DIAGNOSIS OF ADULT FEMALE—In lateral view, posterior of carapace more broadly rounded in ventral half; 4 short processes forming row on infold between list and posterior shell margin; length about 2.04-2.16 mm.
Mandible: Ventral margin of basale with 3 small triaenid bristles near base of endite; dorsal margin of basale with 4 or 5 midbristles.
Maxilla: Ventral margin of basale with 4 midbristles; dorsal margin of basale hirsute.
Sixth limb: Posteroventral margin of end joint with 16 bristles.
Lateral eyes: Absent.
DESCRIPTION OF ADULT FEMALE—Carapace elongate; posterior end more broadly rounded in ventral half in lateral view; both ventral and dorsal margins fairly linear.
Infold: About 60 bristles forming 1 or 2 rows just within and parallel to anterodorsal margin above incisur; about 20 minute bristles present between rows of longer bristles and list; about 25 bristles present on list and between list and incisur; about 50 bristles present below incisur and on anteroventral infold; single row of 20 bristles present along ventral infold to point opposite 1st hyaline spine of posterior list; posterior list with 24 or 25 hyaline spines posterior to about 32 or 33 bristles (7 or 8 long, remaining short); 4 short processes forming row between list and posterior shell margin; 7 to 9 bristles (2 to 4 long, remaining short) present between lowermost hyaline spine on list and lowermost process in area between list and posterior shell margin.
Size: USNM 128964, length 2.04 mm, height 1.17 mm; USNM 128965, length 2.16 mm, height 1.20 mm.
First antenna: 1st and 2nd joints extremely spinous; 2nd joint with 1 long dorsal and 1 short lateral bristle, both with spines; 3rd joint with 6 long spinous dorsal bristles and 1 short bare ventral bristle; 4th joint with 1 long dorsal bristle with short marginal spines and 2 short ventral bristles about same length as ventral margin of 5th joint, both bristles with short marginal spines; ventral margin of 4th joint with spines forming clusters; sensory bristle of 5th joint long with short proximal and 6 long terminal filaments; medial bristle of 6th joint with short marginal spines. Seventh joint: a-claw with minute flat teeth near middle of lateral surface; b-bristle with 5 filaments including stem; c-bristle with 6 filaments including stem. Eighth joint: d- and e-bristles bare, d-bristle about 60 percent length of e-bristle, and tapering to suaged tip; f-bristle almost at right angles to stem, with 5 spinous filaments including stem; g-bristle with 7 filaments including stem.
Second antenna: Protopodite with short medial bristle and slender spines along ventral and dorsal margin and medial surface. Endopodite 3-jointed with long terminal bristle.
Exopodite: 1st joint elongate with hairs forming clusters along distal inner margin; joints 3 to 8 with short spines forming row along distal margin; bristle of 2nd joint reaching 9th joint and with numerous slender spines or hairs along ventral margins; bristles of joints 3 to 8 with natatory hairs; bristles of joints 3 to 5 with few stout proximal ventral spines; 9th joint with 4 bristles, 2 stout with natatory hairs, 2 short with short marginal spines; lateral spine with digitate tip present on 9th joint.
Mandible: Coxale with small bristle at base of endite; ventral margin of dorsal branch of coxale endite with 5 or 6 angular and rounded teeth and short main spine; dorsal bristle proximal to tip of endite with short marginal spines; ventral branch of coxale endite with spines forming 4 or 5 oblique rows and a pointed tip with 2 backward-pointing spines. Basale: endite with 4 spinous terminal bristles, 2 triaenid bristles with 4 and 8 pairs of marginal spines excluding terminal pair, 2 dwarf bristles and small glandular peg; 3rd smaller triaenid bristle with 6 spines (2 on one side, 4 on other or 3 pairs) excluding distal pair present near base of endite proximal to U-shaped sclerotized process; dorsal margin of basale with 2 long terminal bristles with short marginal spines and 5 short spinous midbristles on left limb and 4 on right. Exopodite about one half length of dorsal margin of 1st endopodite joint, with hirsute rounded tip and 2 short subterminal bristles. Endopodite: 1st joint with 3 long spinous bristles; medial and lateral surfaces of 2nd joint with short spines forming clusters; ventral margin with 3 long stout terminal bristles with short marginal spines; dorsal margin with 1 or 2 spinous proximal bristles and stout spinous a-, b-, c-, and d-bristles; 1 long spinous bristle present between b- and c-bristles; 3 spinous medial cleaning bristles forming oblique row between b- and c-bristles; 5 or 6 spinous medial cleaning bristles forming oblique row present between c- and d-bristles; 1 long stout spinous lateral bristle present between c- and d-bristles; 1 long stout spinous medial bristle present distal to base of d-bristle; 3rd joint with short pointed dorsal claw with minute teeth near middle, 3 long spinous clawlike bristles, and 2 slender spinous bristles.
Maxilla: Epipodial appendage short hirsute. Enditc 1 with 1 short and 3 long spinous bristles; endite II with 3 long bristles. Basale hirsute; 1 lateral and 1 bare medial bristle present near base of epipodite; dorsal margin with 3 short bare distal bristles; ventral margin with 4 bare midbristles, 1 short distal bristle and 1 long spinous terminal bristle. Endopodite: 1st joint with 1 short bare middorsal bristle and 1 long spinous 6-bristle; end joint with spinous bristle slightly longer than 6-bristle.
Fifth limb: Epipodial appendage with about 64 bristles. Comb with 1 long stout spinous exopodial bristle and 4 slender bristles near ventral margin distal to base of stout bristle (2 thin bristles may be close to base of stout bristle but not seen with certainty).
Sixth limb: Anterior margin with 1 upper and 1 lower bristle; anteroventral corner with 3 or 4 bristles plus 1 on margin of lateral flap; posteroventral margin with 16 bristles; limb hirsute.
Seventh limb: Each limb with 14 bristles, 8 proximal (4 + 4), 6 terminal (3 + 3), each with 3 or 4 bells; opposing terminal combs with about 14 opposing teeth.
Furca: Each lamella with 9 claws; last 2 or 3 claws bristlelike, straight or bent backward; remaining claws strongly curved, spines present on both concave and convex margins.
Medial eye and rod-shaped organ: Medial eye large with few hairs along dorsal margin; rod-shaped organ broadening proximally. With restriction near middle, tip rounded.
Lateral eye: Absent.
Upper lip: Central part with small anterior spines; each anterolateral lobe with 2 anterior spines, 1 small and 1 large; hirsute lateral flap present on each side of mouth; all lobes hirsute.
Posterior: Dorsal process thumblike with short and long spines (process bent backward on holotype).
Eggs: USNM 128964 with 11 eggs in marsupium.
COMPARISONS—The only species previously assigned to this genus is Archasterope dentata Poulsen, 1965. A. bulla differs from A. dentala in having 4 processes on the posterior infold of each valve and in not having lateral eyes.
REMARKS—USNM 138033, a male (N-l) also without lateral eyes.
DISTRIBUTION—This species was collected on the bottom at one locality in the Magellanic subregion at 279 m depth. It was also collected just outside the Magellanic subregion in a midwater trawl fished at a depth of 1812-2145 m at a station where the bottom depth was 3880-4118 m." (Kornicker 1975, p.384-388)