spines).
Mandible: Basale: Proximal ventral comer with 5 medial bristles (1 stout without rings and with a few minute teeth; 1 stout, ringed distally and with short distal spines; 3 slender completely ringed and either bare or with indistinct short spines); of 5 distal bristles near ventral margin only 2 significantly longer than proximal bristles. Exopodite about 3A length of dorsal margin of 1st endopodial joint 1st endopodial joint with 3 or 4 ventral bristles (1 long, 1 medium, 1 or 2 short). 2nd endopodial joint: dorsal margin with proximal spines and 3 groups of bristles (proximal group with 2 long bristles with wreath of long spines; middle group with 1 short bristle with long spines and 2 long bristles with wreath of long spines; distal group with 1 long bristle with wreath of long spines); ventral margin with long spines, and bristles forming 2 distal groups (2 bristles in proximal group, 3 in terminal group); medial surface with rows of long spines. 3rd endopodial joint with 1 long stout dorsal claw, 1 long bristle-like ventral claw, and 4 short medial bristles Congest claw-like, unringed, with ventral spines; shortest, dorsal, claw-like unringed; others ringed bristle-like) (Figure 58a*).
Fifth Limb: 1st exopodial joint (Figure 58e): with 1 long tooth with about 12 cusps along inner edge and 4 proximal teeth (2 rounded, 2 pointed); anterior side with 3 bristles along distal edge and 1 small bristle on lobe near outer edge. 2nd exopodial joint (Figure 58/): posterior side with row of 3 bristles (long bristle with small bristle on each side), 1 long bristle proximal to row and 1 minute indistinct bristle near outer comer, inner edge of sclerotized joint with 3 teeth along inner edge: proximal with 2 or 3 cusps, middle with 4 cusps, and terminal long slender without cusps. Fused 4th and 5th exopodial joints with 5 bristles with wreaths of long spines.
(The proximal fang-like tooth of the 2nd exopodial joint of the right 5th limb of the holotype bears 3 cusps (Figure 58/) whereas the left limb bears only 2 indicating variability in the number of cusps.)
Sixth Limb (Figure 58g): Endite HI with 1 medial and 7 terminal bristles; endite IV with 1 medial and 6 terminal bristles. End joint with 19 bristles (6 medial, 2 lateral, 11 marginal). (Not all bristles shown.)
Seventh Limb: Each limb with 24 or 25 bristles. Peg (dorsal) side with 12 or 13 tapered proximal bristles with 2 or 3 bells, and 2 terminal bristles with 3 bells; comb (ventral) side with 7-9 tapered proximal bristles with 2 or 3 bells, and 2 terminal bristles with 2 or 3 bells; some bristles with minute indistinct distal marginal spines. Terminus with comb of 17 teeth (teeth increase in length towards middle, but middle tooth only slightly longer than others); side opposite comb with 2 pegs (1 very short) (Figure 58/i).
Furca: Main claws 1,2, and 4 with medial and lateral rows of teeth; medial teeth of claw 1 about same size as lateral teeth;
lamellae following posterior secondary claw with long hairs;
right lamella anterior to left by width of base of claw 1 and with
few spines along anterior margin.
Bellonci Organ (Figure 580: Short segment proximal to middle with indistinct striations; part distal to segment with marginal and terminal hairs.
Eyes: Lateral eye small, with dark brown pigment and 3 or 4 small ommatidia (Figure 58/). Medial eye almost twice as long as lateral eye, with dark brown pigment (Figure 58i).
Posterior of Body: Evenly rounded with hairs at mi- dheight
Y-Sclerite (Figure 58*): With posterior end forming long ventral leg at right angle to long middle segment
COMPARISONS.—Pleoschisma pseudoferox differs in many characters from the description of P.ferox Poulsen (1962:391):
P. ferox is without a lateral eye, whereas P. pseudoferox has a small lateral eye with dark brown pigment; P.ferox has 5 dorsal bristles on the terminal segment of the 7th limb, whereas P.
pseudoferox has only 2, but the main difference is mat the 1st exopodial joint of the 5th limb of P. ferox bears 2 stout teeth, whereas P. pseudoferox has only 1. The juvenile female P.
pseudoferox is larger than the adult female P. pnyx and also bears 4 small proximal teeth at the base of the stout fang-like tooth of the 1st exopodial joint of the 5th limb compared to only 1 tooth on P. pnyx.
Pleoschisma mindax, new species FIGURES 59-61
ETYMOLOGY.—From the Greek mindax (a Persian incense).
HOLOTYPE.—Adult female on slide and in alcohol in the collection of the Museum of Victoria.
TYPE LOCALITY.—Slope 21,36°57.40'S, 15O°18.8O/E,New South Wales, off Eden; depth 220 m.
PARATYPES.—Partly dissected A-l male on slide (2nd antenna, mandible, 5th limb), and in alcohol.
DISTRIBUTION.—Slope 21,220 m.
DESCRIPTION OF ADULT FEMALE (Figures 59-61a-A).—
Carapace oval in lateral view with small but distinct indentation ventral to rostrum (Figure 59a Jb)\ posterior evenly rounded (without projecting caudal process) (Figure 59a/:). Edge of valve folded inward on all margins.
Ornamentation: Surface with abundant round fossae (some shown as crescents in Figure 59a), many with a slender bristle in center, no bristles with broad base. Reticulations observable with transmitted light (Figure 59i).
Infold: Rostral infold of right valve with 3 bristles near anterior edge, and 9 or 10 along inner side of dorsal edge (2 bristles represented by sockets in Figure 59£>); rostral infold of left valve with 3 bristles near anterior edge and none along dorsal edge. Infold of caudal process of right valve with 8 closely spaced bare bristles near dorsal end and close to inner edge of infold, and 2 bristles closer to midwidth ventral to the closely spaced bristles; narrow list near outer edge of infold extending from ventral end of rostrum (not shown in Figure
106
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGYFIGURE 59.—Pleoschisma mindax, new species, adult female, holotype: a, complete specimen from left side, length 2.38 mm; b,c, anterior and posterior, respectively, right valve, iv; d, central adductor muscle attachments, right valve, ov, anterior to right; e, reticulations in vicinity of a bristle on right valve, ov;/,g, right 1 st antenna, mv;
h. distal protopodiie and endopodite, left 2nd antenna, mv; i, left 6th limb, mv.
107
FIGURE 60.—Pleoschisma ndndax, new species, adult female, holotype: a. right mandible, mv (not all bristles shown); b, bristles of 3rd endopodial joint, right mandible, mv; c, endites, left maxilla, mv; d, right maxilla, lv (not all bristles shown); e, bristles of 2nd endopodial joint, left maxilla, mv; / , part of left 5th limb, av (not all bristles shown); g, right 5th limb, pv (endite bristles not shown); h, part of exopodite, right 5th limb, pv; i, left lateral eye, medial eye, and Bellonci organ.
108
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGYFIGURE 61.—Pleoschisma mindax, new species, adult female, holotype: a, 7th limb; b, detail from a; c, pegs on tip of 7th limb opposite limb shown in a; d, caudal furca (missing claw 1 of left lamella dashed; only claw 1 of right lamella shown); e, anterior of body snowing coxale endite of left mandible in natural position near mouth region;/, lateral eye at high magnification (xl 5 ocular, xlOO objective); g. upper lip from left side, anterior to left;
k, posterior of body from right side showing unextruded egg, anterior to right A-l male, paratype: i, distal protopodite and endopodite, right 2nd antenna, mv; j , part of right mandible, lv (not all bristles shown); k. tooth of 2nd exopodial joint of right 5th limb, pv.