"HOLOTYPE— USNM 127506, female, fragments of valves and some appendages in alcohol, remaining appendages on slides.
TYPE-LOCALITY—Eltanin Cruise 14, station 1248, Pacific Quadrant, Antarctic Ocean.
ETYMOLOGY—The specific name "sutura" from the Latin "sutura" [= seam] refers to the suture or seam separating all claws of the furca from the lamellae.
PARATYPES—USNM 127504, 127505, 127507 (2 specimens), all juveniles from same sample as holotype.
DIAGNOSIS—Medial bristle of distoventral pair on 2nd endopodial joint of mandible pointed and not longer than lateral bristle.
Furca: Female with all claws separated from lamella by suture.
DESCRIPTION OF FEMALE— (Carapace of adult holotype consisting of fragments; following description of shell from juvenile paratypes USNM 127504, 127505.) Carapace smooth, oval in lateral view with small but distinct caudal process.
Infold: Infold broad in area of rostrum and caudal process, narrower elsewhere; infold behind rostrum with about 15 bristles; infold of anteroventral margin with about 13 double bristles foiming row paralleling margin; infold of ventral margin without bristles; posterior edge of list along anterior margin of infold of caudal process smooth, with numerous pores, some larger than others, and with single small bristle present at ventral end.
Selvage: Lamella prolongation with smooth outer margin present along anterior and ventral margins and caudal process, being quite broad and striate along lower margin of incisur.
Size: Size of adult unknown. Size of two juveniles, N-l or N-2 stage: USNM 127504, length 2.26 mm, height 1.46 mm; USNM 127505, length 2.15 mm, height 1.44 mm.
First antenna: 1st joint bare, 2nd joint with spines along ventral and dorsal margins; 3rd and 4th joints each with 2 spinous bristles, 1 ventral, 1 dorsal; sensory bristle of 5th joint with 13 long proximal filaments and several short distal filaments; medial bristle of 6th joint short spinous. Seventh joint: a-bristle short spinous; b-bristle with 5 proximal filaments, some with marginal spines, distal margin of b-bristle with about 4 pairs of marginal spines; c-bristle with 9 marginal filaments and bifurcate tip, proximal filaments with marginal spines. Eighth joint: d- and e-bristles bare; f- and g-bristles with about 10 marginal filaments and bifurcate tip, most filaments with marginal spines.
Second antenna: Protopodite with bare medial bristle. Endopodite distinctly 3-jointed: 1st joint with 4 or 5 proximal bristles, 3 or 4 short, 1 longer, and 1 long distal ventral bristle, all bristles bare; 2nd joint elongate with 1 fairly long bare distal bristle; 3rd joint short with 1 long bare terminal filament. Exopodite: bristle of 2nd joint reaching 9th joint and with 12 ventral spines; 9th joint with single or bifurcate lateral spine and 4 bristles, 1 short, bare, 3 long with natatory hairs; bristles of joints 3 to 8 with natatory hairs, but without spines; basal spines present on joints 3 to 8, spine on 8th joint only threefourths length of 9th joint; lateral spine of 9th joint slightly longer than 9th joint; 1st joint with minute spines along dorsal margin.
Mandible: Coxale endite extremely spinous with short peg present between 2 stout terminal spines; short stout bristle present at base of endite. Basale: ventral margin with 2 spinous a-bristles (medial), 1 short spinous b-bristle (lateral) near a-bristles, 2 c-bristles, 1 short bare, 1 medium spinous, and 2 spinous d-bristles; minute process present on margin between c-bristles; dorsal margin with 3 spinous bristles. Exopodite reaching end of 1st endopodite joint and with 2 spinous bristles. Endopodite: 1st joint with 3 ventral bristles, 2 short, 2 long, and short spines forming row near distal margin; dorsal margin of 2nd joint with 4 long, 2 medium, and 8 short bristles, all with bases on proximal half of margin; ventral margin of 2nd joint with 2 single short slender distal bristles and terminal group with short lateral bristle and medial spine; end joint with 3 claws and 4 bristles, each claw with several minute proximal teeth along concave margin.
Maxilla : First endite with 10 bristles, some with triaenid tips, others with either broad tip, or normally tapering (tips of bristles similar to those illustrated for Gigantocypris muelleri Poulsen (Poulsen, 1962:62, fig. 28); 2nd endite with 6 bristles, some with triaenid tips; 3rd endite with 5 bristles, some with triaenid tips; 1 small bristle present on basale near base of 3rd endite. Coxale with usual stout plumose bristle. Basale with 2 bristles on distal margin near base of exopodite, 1 long, 1 short. Exopodite hirsute with 1 hirsute proximal bristle and 2 terminal bristles, outer terminal bristle with long marginal hairs, inner bristle with widely separated short spines. Endopodite 1st joint: short spines on anterior margin and long hairs on posterior margin; cutting edge of joint not well defined; 2 a-bristles present, longer of these with long marginal hairs continuing to tip, shorter bristle with short marginal spines; 2 or 3 6 bristles present, 2 stout pectinate, 1 short with single tooth near tip. Endopodite 2nd joint: 5 a-bristles present, 2 posterior of these with few marginal teeth, other bristles bare; 3 b-bristles, 3 c-bristles, and 3 d-bristles present, all except outer c-bristle pectinate; 2nd joint bending inwards forming almost right angle with 1st joint.
Fifth limb: Epipodial appendage with 62 bristles; protopodite with usual anterior process. Exopodite: main tooth of 1st joint with proximal peg and 6 pectinate teeth; 1 spinous bristie present proximal to peg; 2nd joint with 1 spinous proximal posterior bristle, 1 spinous proximal anterior bristle, and distally, 4 or 5 pectinate a-bristles, and 6 pectinate b-bristles; 3rd joint with 3 spinous bristles on inner lobe and 2 on outer lobe; 4th and 5th joints separated by distinct suture; 4th joint with 3 spinous bristles on inner side; 5th joint with 2 spinous bristles; no process present between 4th and 5th joints, although a few stout spines were observed on 1 limb; 3rd to 5th joints hirsute. Three endites present.
Sixth limb: Epipodial appendage with 4 bare bristles; 1st endite with 3 or 4 spinous bristles, 2 or 3 medial, 1 terminal; 2nd endite with 4 or 5 spinous bristles; 3rd endite with 4 or 5 spinous bristles, 1 or 2 medial, 3 terminal; 4th endite with 4 spinous bristles, 2 medial, 2 terminal; 4th endite slightly smaller than 3rd. End joint with 16 or 17 bristles: anteroventral margin with 11 broad bristles with long proximal and short distal marginal spines; posteroventral margin with 1 spinous bristle and 4 longer hirsute bristles; small space present between anteroventral and posteroventral bristles; 1 short spinous bristle with base on medial surface present near 4th bristle in anteroventral group of right limb of holotype, but not on left; medial and lateral surfaces and ventral margin of end joint hirsute.
Seventh limb: (Both 7th limbs of only adult in the collection are missing. Therefore, the 7th limbs of a juvenile, USNM 127505, is described here. The juvenile bears 7 claws on the furca and is either an N-l or, more likely, an N-2 instar). Each limb with 4 bristles in terminal group and 1 or 2 bristles in proximal group, each bristle tapering distally and with 1 bell. Terminal comb consisting of 5 teeth including 1 short spinous tooth on each end of comb; fingerlike peg, which may have spines, present opposite comb.
Furca: Each lamella with 9 claws separated from lamella by suture, each claw decreasing in length dorsally; base of 3rd claw only very slightly narrower than base of 4th claw, or both claws about same width; all claws, except possibly last 2, with medial and lateral row of teeth along posterior margin; anterior margin of lamella with few short spines.
Rod-shaped organ and eyes: Rodshaped organ short, tapering. Lateral eyes absent, medial eye not well defined.
Upper lip: Lip consisting of anterior unpaired part and 1 pair of posterior tusks followed by unpaired hirsute lobe; anterior unpaired part with several rows of glandular openings on ventral surface; tusks with glandular openings forming row at tip and 4 or 5 irregular rows near middle of lateral surface.
Genitalia and brushlike organ: Genitalia on each side represented by sclerotized ring. Brushlike organ consisting of about 12 minute bristles located dorsal to genitalia near base of 7th limb.
COMPARISONS—The furca of Vargula sutura differs from previously described species of the genus in having all claws of the furca separated from the lamellae by sutures. Also, the medial bristle of the distoventral pair on the 2nd endopodial joint of the mandible is pointed and not longer than the lateral bristle.
DISTRIBUTION—This species was collected at only one locality in the Pacific Quadrant of the Antarctic region at a depth of 3386-3477 m." (Kornicker 1975, p.166-171)
