Alternochelata nealei Kornicker & Caraion 1978

Alternochelata nealei

HOLOTYPE.—“Grigore Antipa” 293, female with large unextruded eggs, length 1.18 mm, left valve and some appendages in alcohol, remaining appendages on 2 slides; right valve gold-plated.

TYPE-LOCALITY.—Station X013.

ALLOTYPE.—“Grigore Antipa” 294, adult male, length 1.27 mm; left valve and some appendages in alcohol, remaining appendages on slide; left valve gold-plated, in 2 parts; from same sample as holotype.

ETYMOLOGY.—The species is named for Dr. John W. Neale.

PARATYPES.—USNM 154199, 1 ovigerous female from station X048; USNM 156591, 1 specimen from station A4b; USNM 156592, 13 specimens including 3 ovigerous females from station A6b; USNM 156593, 15 specimens from station A7b; USNM 156594, 1 specimen from station A8a; USNM 156596, 1 adult male from station A6b; USNM 156608, 2 specimens from station A10b; USNM 156620, 62 specimens from station X013; “Grigore Antipa” 461, 38 specimens from station X013; USNM 156621, 236 specimens from station X015; USNM 156622, 136 specimens from station X013; USNM 156628, 77 specimens from station X068; USNM 156633, 3 specimens from station X041; USNM 156637, 1 specimen from station X057; USNM 156638, 4 specimens from station X052; USNM 156639, 5 specimens from station X044; USNM 156640, 1 specimen from station X039; USNM 156641, 1 specimen from station X031 USNM 156642, 1 specimen from station X005.

DESCRIPTION OF FEMALE (Figures 56–58).—Carapace oval in lateral view with greatest height near middle of dorsal margin and greatest posterior extension near middle of posterior margin (Figures 56, 57a); rostrum rounded anteriorly and projecting ventrally only slightly over shallow but distinct incisur; posterior evenly rounded, without projecting caudal process.

Ornamentation: Surface with large round fossae within weak reticulations (Figure 56); no ribs; lateral surface, anterior, ventral, and posterior margins with long and short hairs broadening near base.

Infold (Figure 57c, d): Broad along anterior, ventral, and posteroventral margins; infold on rostrum with 7 feathered bristles forming row paralleling anterior margin (Figure 56 c); 1 long bristle at middle of upper margin of incisur, and 1 short bristle at inner end of incisur; broad part of anteroventral infold with 6 parallel ridges proximal to thin list bearing 8 bristles; 1 bristle present on infold between ridges and incisur; middle part of ventral infold bare; posteroventral and posterior infold with row formed of 10 or 11 clusters consisting of single or paired bristles (Figure 57d).

Selvage (Figure 56, 57c): Fringed lamellar prolongation present along anterior, ventral, and posterior margins.

Central Muscle Attachment Scars (Figure 57b): Consisting of about 20 individual scars.

Size: “Grigore Antipa” 293, length 1.18 mm, height 0.85 mm; USNM 156592, 3 specimens: length 1.20 mm, height 0.83 mm; length 1.21 mm, height 0.86 mm; length 1.25 mm, height 0.88 mm.

First Antenna (Figure 57e, f): 1st joint: long hairs on medial surface and short spines along ventral margin. 2nd joint: 3 bristles with faint marginal spines (1 lateral, 1 ventral, 1 dorsal); spines forming clusters along dorsal margin, on medial surface near dorsal and ventral margins, and near distal end of lateral surface. 3rd joint: short with 2 spinous bristles (1 ventral, 1 dorsal); spines forming clusters along dorsal margin and on medial surface near dorsal margin; lateral side of 3rd joint about twice length of medial side. 4th joint: distinctly separated by suture from 3rd joint, with 4 spinous bristles (3 ventral, 1 dorsal; ventral bristles with long and short spines, dorsal bristle with short spines); spines forming clusters along ventral and dorsal margins and on lateral surface near ventral margin. 5th joint: spines forming clusters along dorsal margin and on lateral surface at distal margin; sensory filament with 1 short proximal filament (not shown in Figure 57f) and bifurcate tip (not shown in Figure 57f); 6th joint; very short; medial bristle short with marginal spines. 7th joint: a-bristle about same length as bristle on 6th joint, with short marginal spines; b-bristle bare, about one-third longer than a-bristle; c-bristle with 1 short proximal filament (not shown in Figure 57f) and bifurcate tip, same length as sensory bristle of 5th joint. 8th joint: d- and e-bristles bare with fused base and blunt tips, same length as c-bristle; f-bristle without proximal filament but with bifurcate tip (not shown in Figure 57f), slightly shorter than c-bristle; g-bristle with 1 short proximal filament (not shown in Figure 57f) and bifurcate tip (not shown in Figure 57f), same length as c-bristle.

Second Antenna: Protopodite bare. Endopodite 2-jointed (Figure 57g, h): 1st joint with 5 small bare bristles; 2nd joint elongate with rounded tip and long subterminal bristle with short marginal spines. Exopodite: 1st joint with short medial spine on distal margin; joints 2–8 with short spines forming row along distal margin; bristle of 2nd joint bare, reaching 9th joint; bristles of joints 3–5 bare with pointed tips; bristles of joints 6–8 and 4 long bristles of 9th joint broken, with natatory hairs on stumps; 9th joint, in addition to 4 long broken bristles, with 3 short spinous bristles at dorsal corner.

Mandible (Figures 57i–k, 57a–d): Coxale endite bifurcate, with secondary teeth and long spines; minute peg present in valley between main spines (Figure 57j). Basale: proximal ventral group with 1 long bristle with short marginal spines and 3 short bristles, 2 of these pectinate; 2 equal length bristles with marginal spines present on ventral margin distal to middle; dorsal margin with short midbristle with short marginal spines and 2 subterminal bristles, shorter of these with short marginal spines, other with long proximal and short distal spines. Exopodite absent. Endopodite (Figures 57a,d, 58a–d): 1st joint with 2 short ventral bristles and spines forming rows on medial surface; 2nd joint with spines forming rows on medial surface; dorsal margin with 5 or 6 bristles (4 in vicinity of middle, 1 or 2 proximal to middle (Figure 57i, k)); ventral margin with stout terminal claw with serrated inner margin, but without proximal inner tooth (Figure 58a,b); tip of claw distal to serrations fingerlike (Figure 58d); 2 small ventral bristles and small spade-shaped sclerotized medial process present near base of claw (Figure 58b); 3rd joint with 2 large claws (Figure 58a): inner claw with large distal and small proximal teeth along ventral margin: outer claw with minute teeth along ventral margin and without distodorsal node; lateral surface with 2 short bristles with long marginal hairs present ventral to bases of claws; 3 short bristles present medial to bases of claws.

Maxilla (Figure 58e): Precoxale and coxale with fringed epipodial appendage; coxale with 1 distoanterior bristle with short marginal spines. Endite I with 5 stout pectinate bristles and 2 slender bristles with long proximal and short distal spines; endite II with 2 stout pectinate bristles and 2 slender spinous bristles; endite III with 3 stout pectinate bristles (not all shown in Figure 58e), 1 or 2 slender spinous bristles, and 1 proximal lateral bristle with short spines. Basale with 1 slender distoanterior bristle with short marginal spines, 1 distoposterior bristle near exopodite, and 1 short spinous bristle near middle of medial margin (the latter 2 bristles could be on 1st endopodite joint). Exopodite short with 3 bristles (Figure 58e). Endopodite: 1st joint with 1 α and 1 β-bristle, both with short marginal spines; dorsal margin of joint with short spines; 2nd joint with 2 stout pectinate clawlike bristles, 2 a-bristles with short marginal spines, and 3 terminal bristles, some pectinate.

Fifth Limb (Figure 58f,g): Epipodial appendage with 47 bristles. Endite I with 2 spinous bristles and short triangular process; endite II with 3 spinous bristles and short triangular process; endite III with about 4 spinous and pectinate bristles and short triangular process. Exopodite: first joint with main tooth consisting of 3 large prongs, proximal of these with 1 small marginal tooth, middle prong with 3 marginal teeth, distal prong with 2 marginal teeth; small node may be present near proximal prong; short bristle present near node; middle of anterior margin of joint with 1 spinous bristle; inner end of joint anterior to main tooth forming sclerotized triangular tooth. Second joint with large triangular tooth with 3 prongs, each prong with 2 marginal teeth; outer edge of triangular tooth with small hirsute bristle near rounded end; posterior side of joint with 1 proximal bristle near inner margin and distal to this, a pair of bristles; 3rd joint with 3 bristles on inner lobe and 2 on outer lobe, the latter hirsute; 4th and 5th joint fused, with 3 or 4 terminal bristles.

Sixth Limb (Figure 58j): 2 plumose bristles in place of epipodial appendage; endite I with 3 short spinous bristles (2 stout with long spines, 1 slender with short spines); endite II with 3 bristles, 2 long, 1 short, all with long proximal and short distal spines; endite III with 3 bristles, middle bristle longer than others, all with long proximal and short distal spines; 4th endite with 2 long bristles with long proximal and short distal spines; end joint with anterior part with 3 slender ventral bristles with long proximal and short distal spines, and posterior part with 4 stout plumose bristles separated by marginal indentations; lateral and medial surfaces of endites II to IV and end joint hirsute.

Seventh Limb (Figure 58k): Terminal comb with about 11 alate teeth with small teeth near bases opposing 2 bare recurved pegs; each limb with 10 bristles, 4 in proximal group (2 on each side), and 6 in terminal group (3 on each side); each bristle with 2 to 5 bells and distal marginal spines.

Furca (Figure 58m): Each lamella with 3 strong main claws followed by 1 short secondary claw, 1 short main claw, and 5 short secondary claws; long hairs present medially at bases of main claws and following secondary claws; claw 1 with teeth forming medial and lateral row; other main claws with teeth forming 1 or 2 rows; secondary claws between main claws 3 and 5 with spines forming row along each margin; posterior 5 secondary claws with few marginal spines.

Rod-shaped Organ: Elongate, 1-jointed with widened middle section; faint spines present on broad middle section and proximal half of elongate distal section, tip rounded (Figure 58l).

Eyes: Lateral eyes absent; medial eye pigmented, bare (Figure 58l).

Upper Lip (Figure 58h): Small, rounded.

Posterior (Figure 58i): Clusters of long hairs present near middle of dorsal margin.

Y-Sclerite: Linear with short upturned distal end, without ventral branch.

Eggs: “Grigore Antipa” 293, with 2 or 3 large unextruded eggs.

DESCRIPTION OF ADULT MALE (Figure 59).—Carapace more elongate than that of female (Figure 59a); lower margin of rostrum forming almost right angle with anterior margin of valve to form incisur more open than that of female carapace.

Ornamentation: Surface fossae similar to those of female; long hairs present along anterior, ventral, and posterior margins, and on posterior valve surface.

Infold, Selvage, Central Muscle Attachment Scars: Similar to those of female.

Size: USNM 149317, length 1.27 mm, height 1.00 mm; USNM 156596, length 1.38 mm, height 0.81 mm.

First Antenna (Figure 59b,c): 1st joint: spines forming clusters on distal part of medial surface. 2nd joint: abundant clusters of spines on medial and lateral surfaces, joint otherwise similar to that of female. 3rd joint: spines forming 3 clusters across middle of ventral margin, limb otherwise similar to that of female. 4th joint: distinctly separated from 3rd, with 5 bristles (4 ventral, some with long proximal and short distal spines, 1 dorsal with long proximal and short distal spines); ventral and dorsal margins, medial surface, and dorsal part of lateral surface with spines forming clusters. 5th joint: small, triangular, inset between ventral parts of 4th and 6th joints; sensory bristle with broad proximal part almost reaching distal end of 6th limb and bearing about 33 filaments and stout terminal bristle with bifurcate tip. 6th joint: short spinous lateral bristle near dorsal margin reaching past end of limb. 7th joint: a-bristle slightly shorter than bristle of 6th joint and with short marginal spines; b-bristle stout, about 3 times length of a-bristle, with 3 short filaments near middle; c-bristle long, reflexed, with 12 marginal filaments. 8th joint: d- and e-bristles bare, longer than b-bristle; f-bristle similar to c-bristle but shorter, with 8 marginal filaments (f-bristle not shown in Figure 59c); g-bristle slightly longer than d-bristle, with 1–2 marginal filaments and bifurcate tip.

Second Antenna: Protopodite bare. Endopodite 3-jointed; 1st joint with 6 small bristles (5 proximal, 1 distal); 2nd joint elongate with 2 long ventral bristles just proximal to middle; 3rd joint elongate, reflexed with 2 short subterminal bristles (Figure 59e); central part of 3rd joint with 10–13 small toothlike processes. Exopodite (Figure 59d): 1st joint with short medial spine on terminal margin and numerous spines forming clusters distally; 2nd joint short; 3rd joint about 3 times length of 2nd; joints 4–9 smaller than 2nd joint; joints 2–8 with spines forming row along distal margin and 1–3 (usually 1) small basal spine at base of bristle; bristle of 2nd joint bare, pointed, reaching 8th joint; bristles of joints 3–8 with natatory hairs and pointed tip; 9th joint with 6 bristles (4 long pointed, with natatory hairs, 2 very short with marginal spines); 9th joint without lateral spine.

Mandible (Figure 59f,g).—Coxale endite represented by small triangular process (Figure 59g); 2 smaller processes present adjacent to endite (Figure 59g). Basale: medial side near ventral margin with 6 proximal spinous bristles (2 long, 1 medium, 3 short), and 2 long spinous bristles distal to middle; dorsal margin with 1 short spinous midbristle and 2 longer spinous subterminal bristles (not all shown in Figure 59f); medial surface and dorsal margin with spines forming clusters. Exopodite appears fused to lateral side of 1st endopodite joint at dorsal margin and is full length of joint. Endopodite: 1st joint with 3 spinous ventral bristles and numerous medial spines forming short rows; 2nd joint with spines forming short rows on medial surface; dorsal margin with 7 spinous bristles (not all shown in Figure 59f); ventral margin with bristles forming 2 distal groups: proximal group with 2 bristles, distal group 4 spinous bristles; 3rd joint with 2 lateral claws with spines along ventral margin (inner claw about two-thirds length of outer claw), and 5 shorter spinous medial bristles (all bristles not shown in Figure 59f).

Maxilla (Figure 59h): Precoxale and coxale with fringed epipodial appendage; coxale with 1 stout distoanterior (dorsal) bristle with long marginal spines. Endite I with 1 proximal ventral bristle and 5 terminal bristles; endite II with about 6 terminal bristles; endite III with about 7 terminal bristles. Basale with 1 distoanterior (dorsal) bristle and 1 short medial bristle near middle of distal margin (this could be on proximal part of endite III). Exopodite short with 3 subequal spinous bristles (Figure 59h). Endopodite: 1st joint hirsute with 1 α and 1 β-bristle; 2nd joint with 8 bristles (2 slightly longer than others and stouter).

Fifth Limb (Figure 59i): Epipodial appendage with 48 bristles. Endite I with 2 short bristles; endite II with 2 or 3 short spinous bristles; endite III with 1 stout bristle with long proximal hairs and short distal spines, and 3 or 4 short slender bristles with short marginal spines. Exopodite: 1st joint with 1 short proximal bristle and 2 or 3 unsegmented terminal bristles; 2nd joint with 6 bristles; 3rd joint with 2 bristles (1 of these unsegmented with marginal spines, other segmented) on inner lobe and 2 long stout hirsute bristles on outer lobe; 4th and 5th joint fused, with 4 bristles; outer lobe of 3rd joint and joints 4 and 5 hirsute.

Sixth Limb: Similar to that of female except only 2 bristles on endite I, both with long spines; endite IV of one limb with 1 single bristle and 1 double bristle with fused proximal part.

Seventh Limb: Terminal comb with 11–13 alate teeth with small teeth near bases opposing 2 short pegs (1 of these may have marginal spines); each limb with 8 bristles (4 in both proximal and terminal groups, 2 on each side); each bristle with 1–3 bells and distal marginal spines.

Furca: Similar to that of female.

Rod-shaped Organ: Longer than that of female and not as wide in middle part (Figure 59j); marginal spines not observed with magnification of × 200; tip rounded as on that of female.

Eyes: Lateral eyes well developed with about 14 ommatidia (Figure 59k); medial eye pigmented, bare, smaller than lateral eye (Figure 59j).

Upper Lip (Figure 59j): Similar to that of female.

Posterior: Bare.

Copulatory Organ (Figure 59l,m): Each limb consisting of 2 short lobes with 1 or 2 small bristles.

Y-Sclerite (Figure 59n): Without ventral branch.

COMPARISONS.—The new species, A. nealei, differs from A. polychelata Kornicker, 1958, in not having a distinct caudal process on the carapace. Also, the main claws of the furca are claws 1–3, 5 on A. nealei, and claws 1, 2, 4, 6 on A. polychelata.