Harbansus flax Kornicker ex Kornicker & Thomassin 1998

Harbansus flax

ETYMOLOGY.—From the Anglosaxon fleax (linen).

HOLOTYPE.—A–1 female on slide and in alcohol.

TYPE LOCALITY.—BT-259.

PARATYPES.—None.

DISTRIBUTION.—Collected only at type locality.

DESCRIPTION OF A–1 FEMALE (Figures 45–47).—Each valve with overhanging rostrum, well-developed caudal process, poorly defined lateral ribs, and numerous fairly large shallow fossae (Figure 45a–d). Anterior edge of rostrum with 13–15 minute tubercles (Figure 45d,e). Rostrum with narrow rib (with scalloped dorsal edge) near midheight extending almost to anterior margin of rostrum, and a ridge with scalloped dorsal edge close to dorsal margin of rostrum (Figure 45d). Single bristles present along valve margins and distributed sparsely elsewhere (Figure 45c). (All surface bristles except those along the ventral margin disappeared on valves of holotype kept in glycerin for 9 years; because of this it is not certain whether a few divided bristles might have been initially present; bristles shown in Figure 45c were drawn by Carolyn Gast in about 1984; bristles of the infold were not affected by the glycerine.)

Infold: Infold of rostrum with row of 4 bristles and paired bristles at inner end of incisur (Figure 45e); 1 small bristle ventral to inner end of incisur. Infold of caudal process with row of 5 setose bristles along anterior edge of “pocket” (Figure 45f). Anteroventral infold with 4 or 5 ridges parallel to valve edge.

Selvage: Wide lamellar prolongation divided at inner end of incisur.

Carapace Size (length, height in mm): Holotype, 0.87, 0.47.

First Antenna (Figure 45g,h): 1st joint bare. 2nd joint with dorsal spines but without bristles. 3rd joint short with ventral spines and 3 bristles (2 dorsal, 1 medial near ventral margin). 4th joint elongate with indistinct ventral spines and 4 bristles (2 dorsal, 2 ventral). Sensory bristle of 5th joint with 1 short proximal filament, 1 distal filament, 3 subterminal filaments, and tip with 2 minute papillae (Figure 45h). 6th joint minute, fused to 5th, with short medial bristle near dorsal margin (Figure 45g). 7th joint: a-bristle about same length as 5th joint, with minute indistinct marginal spines (Figure 45h); b-bristle shorter than bristle of 5th joint, with 2 distal filaments and tip with 2 minute papillae; c-bristle same length as sensory bristle, with 3 short proximal filaments, 3 subterminal filaments, and tip with 2 minute papillae. 8th joint: d- and e-bristles same length as c-bristle, bare with blunt tips; f-bristle about same length as c-bristle, with 2 short proximal filaments, 2 longer subterminal filaments, and tip with 2 minute papillae; g-bristle about same length as c-bristle, with 2 short proximal filaments, 3 longer subterminal filaments, and tip with 2 minute papillae.

Second Antenna: Protopodite bare (Figure 46a). Endopodite 2-jointed (Figure 46a,d): 1st joint with 1 or 2 small bristles; 2nd joint with broadly rounded tip (tip either bare (left limb of holotype, Figure 46d), or with long terminal bristle (right limb of holotype, Figure 46a), and long ventral bristle with long spines near midlength. Exopodite (Figure 45b,c): 1st joint with minute medial bristle on distal margin (not shown); bristle of 2nd joint reaching past 9th joint, with 6 stout proximal ventral spines followed by slender ventral spines (Figure 46b); bristles of joints 3–8 with 6–8 stout ventral spines and distal natatory hairs (bristle of 5th joint shown in Figure 46c); bristle sutures more closely spaced distally (in part bearing natatory hairs); 9th joint with 2 short spinous bristles (ventral bristle with ventral spines (2 proximal spines stouter); dorsal bristle with few minute spines) (Figure 46c); joints 4–8 with stout basal spines (Figure 46c); joints 2–8 with indistinct minute spines along distal edge. (The right exopodite of the holotype is aberrant in having only 8 joints and 4 bristles on the terminal 8th joint; the long terminal bristle on the 2nd joint of the right endopodite is unusual for the genus and also could be an aberrancy.)

Mandible (Figure 46e): Coxale endite spinous with bifurcate tip. Basale: medial surface with 4 small bristles near ventral margin (3 proximal, 1 near midlength); lateral surface with long hairs near ventral margin and 2 long spinous bristles; ventral margin with 1 long spinous terminal bristle; dorsal margin with 3 bristles (1 near midlength, 2 terminal). Exopodite about length of dorsal margin of 1st endopodial joint, hirsute near tip, with 2 bristles (terminal bristle about length of proximal bristle). 1st endopodial joint with 3 ventral bristles (2 long with wreaths of long spines, 1 short with small spines). 2nd endopodial joint: ventral margin with 2 pairs of distal bristles (medial bristle of proximal pair longer than others); dorsal margin with 5 or 6 bristles near midlength (2 with bases on lateral side; proximal marginal bristle (present only on right limb of holotype) and distal medial bristle short). 3rd endopodial joint with 3 unringed claws (dorsal claw minute and indistinct; large claws with minute ventral spines) and 3 ringed bristles).

Maxilla: Endites I and II each with 6 bristles; endite III with 7 terminal bristles (Figure 46f). Basale with 3 long terminal bristles (1 spinous ventral, 1 bare dorsal (this could be on the coxale), and 1 spinous lateral at midwidth) (Figure 46g). Exopodite small, with 3 bristles (2 long, 1 short) (Figure 46g). Endopodite: 1st joint with 1 spinous alpha-bristle and 3 beta-bristles (Figure 46h); 2nd joint with 9 bristles including 3 claw-like bristles (Figure 46i). (The single limb studied is missing the proximal part of endite III so that the presence of a proximal bristle could not be determined, but one is usually present in members of the genus).

Fifth Limb: Endite I with 1 long and 1 short bristle (Figure 47a); endite II with about 5 bristles; endite III with about 9 bristles. Exopodite: 1st joint with 2 anterior bristles near midwidth of distal margin and 1 small bristle near outer distal corner (Figure 47b); main tooth with 4 cuspate teeth (proximal tooth could be interpreted to be part of 2nd tooth) and short spinous proximal bristle (Figure 47a,b). 2nd joint with large squarish tooth with small node on inner edge and 4 posterior bristles (1 proximal and row of 3 distal (1 long bristle with small bristle on each side)) (Figure 47a,b). 3rd joint with 3 bristles on inner lobe and 2 on outer lobe (Figure 47a). 4th and 5th joints fused, with total of 5 or 6 bristles (Figure 47a). (Not all spines and rings on bristles shown.)

Sixth Limb (Figure 47c): With 1 epipodial bristle. Endite I small with 3 bristles; endite II elongate with 3 spinous terminal bristles; endites III and IV broad (about same width) each with 5 spinous terminal bristles. End joint not prolonged posteriorly, with 7 bristles (5 spinous anterior, 2 plumose posterior). (Not all spines and rings shown on bristles.)

Seventh Limb (Figure 46j): Each limb with 2 proximal bristles (1 on each side) with distal spines but no bells, and 4 terminal bristles (2 on each side) with distal spine and 2 bells; distal bell with very long clapper. All bristles taper distally. Terminus with comb with 3 recurved teeth opposite 1 recurved peg

Furca (Figure 47d): Each lamella with 6 claws; claws 1, 2, and 4 stout; claws 3, 5, and 6 shorter, slenderer, and with broad base; all claws with short teeth along posterior edges; claw 1 with long slender distal medial tooth); right lamella anterior to left by width of base of claw 1.

Bellonci Organ (Figure 47e): Distal end missing from USNM 194213, stump with 1 visible suture.

Eyes: Medial eye bare unpigmented (Figure 47e). Lateral eyes of holotype not visible in lateral view, but a small unpigmented process observed on each side of anterior of body viewed dorsally (after 1st and 2nd antennae were removed) may be lateral eyes (Figure 47f).

Upper Lip (Figure 47f): With minute spines or processes at anterior tip.

Genitalia: None observed.

Posterior of Body: Bare.

Y-Sclerite (Figure 47g): With ventral branch.

COMPARISONS.—The 1st antenna of H. flax differs from previously described species of the genus in lacking a dorsal bristle on the 2nd joint. It is possible that lack of that bristle on H.flax is a juvenile character; however, except for the absence of the bristle on one of the limbs of an A–1 female of H. thrix, which was considered an aberrancy by Kornicker (1992:101) because other bristles also were missing from the limb, known juveniles of other species do not lack the bristle. However, if future collections of adults of H. flax in Madagascar show adults to have a dorsal bristle on the 2nd joint, H. flax should probably be referred to H. thrix, which it resembles in other characters.

RUTIDERMATIDAE Brady and Norman, 1896

RUTIDERMATINAE Brady and Norman, 1896

Rutiderma Brady and Norman, 1896

TYPE SPECIES.—Rutiderma compressa Brady and Norman, 1896.

COMPOSITION AND DISTRIBUTION.—The genus contains about 30 species of which two (R. arx Kornicker, 1992, and R. rex Kornicker, 1992) were collected in the western Indian Ocean. The former species as well as two new species are in the present collection.