| Size | small | large |
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| Carapace | transversely ovate | squarish to distinctly broader than long, transversely ovate (larger specimens) |
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| Dorsal surface of carapace | gently convex and swollen, with shallow grooves | gently to strongly convex, with rather distinct grooves on large specimens |
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| Anterolateral margin | arcuate; one very low epibranchial tooth separated from external orbital tooth by very small notch (often undiscernible or, when absent, margin appearing entire) | gently convex to strongly arcuate (larger specimens); with three teeth: one external orbital tooth and two epibranchial teeth, variously developed and arranged in variable manner |
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| Posterolateral margins | distinctly converging towards posterior carapace margin | subparallel to more or less converging towards posterior carapace margin (larger specimens) |
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| Antennule | obliquely folded; basal article well developed and exposed; article 2 obliquely folded, entirely visible | horizontally folded; basal article squarish, exposed; article 2 small, only partially visible |
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| Antenna | basal article (2+ 3) J-shaped, bearing article 4 on short inner side; article 5 well visible; short flagellum bent; no orbital hiatus | basal article (2+ 3) squarish; article 4 almost not visible; flagellum bent down in orbital hiatus |
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| Front | not much deflexed, thick, almost entire | deflexed, with inner and outer subfrontal lobes developed |
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| Orbit | delimitated, sheltering most part of podophtalmite | only basally delimitated, sheltering proximal part of podophtalmite; a pointed tooth at inner angle |
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| Suborbital ridge | thick, tuberculate, possibly acting as pars stridens (inner margin of P1 merus with ridge, possibly acting as plectrum) | longer, thinner, smooth |
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| Proepistome | wide, rectangular, with median process | small, dome-shaped; encircled by developed inner frontal lobes |
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| Buccal frame | elongate-rectangular, delineated laterally | shorter, quadrate, subcircular to rhomboid, not delineated laterally |
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| Epistome: anterior margin | straight, thick, tuberculate | as two concave thin edges joining medially |
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| Mxp3 | rectangular, distinctly longer than broad, with merus distinctly longer than ischium | shorter, squarish, as broad as long, with merus barely longer than ischium |
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| Ischium | with slight longitudinal sulcus, bordered by setose ridge | with slight short sulcus; no setose ridge |
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| Merus | with very deep oblique depression all along, bordered by setose ridge | with slight depression; no setose ridge |
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| Palp | inserted near latero-external angle of merus; palp short, with three mobile articles externally visible, first article encroaching on margin of epistome | inserted near middle of anterior margin of merus; palp short, with three mobile articles externally, all included in buccal cavity |
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| Mxp3 exopod | exposed, slender, with flagellum | exposed, slender, with vestigial flagellum |
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| Pterygostomial area | not setose | very setose |
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| Subhepatic area | sligthly setose | not setose |
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| Sterno-pleonal cavity | shallow, its extremity distant from suture 2/3 | very deep; its extremity not so distant from suture 2/3 |
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| Male pleon | relatively short; somite 6 wide, with margins straight proximally, convex distally | longer; somite 6 long, narrowing distally, trapezoidal, with straight margins |
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| Telson | short, bluntly rounded | long, acutely triangular |
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| Female pleon | not described | wide, leaving laterally and especially anteriorly a sternal portion exposed, in addition to episternites; telson in shape of a large triangle |
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| Thoracic sternum | sternite 1 as a spine in continuity with sternite 2; sternite 2 as a large dome-shaped plate, with convex margins; sternites 3 and 4 fused, with slightly sinuous lateral margins | sternite 1 as a spine in lower level than sternite 2; sternite 2 narrower, with straight margins; sternites 3 and 4 fused, with slightly concave lateral margins |
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| Pleonal locking structure in males | a small button in anterior third of sternite 5; apparatus not functional | a largely developed and salient rugose prominence, rather close to suture 4/5. Apparatus seemingly functional: pleonal socket with calcified border |
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| Male gonopore | sternal, distant from P5 | sternal, distant from P5 |
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| Penis | emerging distinctly far from suture 7/8, on middle of sternite 8, crossed by sulcus joining P5 coxo-sternal condyle | emerging distinctly far from suture 7/8, on very small sternite 8 |
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| G1 | relatively short, stout | relatively elongated, slender |
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| Setal pouch | short setae on P2 and P3 and on P3 and P4 coxae, forming two small setal pouches between P2/P3 and P3/P4 | soft and long setae on P3 and P4 coxae forming a large setal pouch between P3/P4 |
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