Pylochelidae (Forest, 1987)

McLaughlin, P. A., 2003, Illustrated keys to families and genera of the superfamily Paguroidea (Crustacea: Decapoda: Anomura), with diagnoses of genera of Paguridae, Memoirs of Museum Victoria 60 (1), pp. 111-144 : 113

Key to genera of Pylochelidae

1. Shield incompletely separated from posterior carapace, linea transversalis not apparent medially ( Figs 3c, e ); telson divided into anterior and posterior articulating plates ( Fig. 5a )............................... 2

— Shield completely separated from posterior carapace, linea transversalis clearly apparent medially ( Figs 3d, f–h ); telson not divided into anterior and posterior articulating plates ( Fig. 5b )............................... 3

2. Shield approximately as long as broad; anterior margin with median concavity and rarely rostral spinule ( Fig. 3c ); corneas always hemispherical..................................... Pylocheles A. Milne-Edwards, 1880

— Shield distinctly broader than long; anterior margin with rounded rostral lobe ( Fig. 3e ) or with short rostral spine; corneas reduced or absent ( Fig. 3e ).......................................... Cheiroplatea Bate, 1888

3. Penultimate segments of ocular peduncles without ocular acicles developing squamiform or spiniform anterior projections ( Figs 3f, h )......................... 4

— Penultimate segments of ocular peduncles with ocular acicles each developing triangular or squamiform anterior projection ( Figs 3d, i, j, m )..................... 6

4. Penultimate segments of ocular peduncles each with well developed, rounded or subrectangular plate ( Fig. 3f ); telson with pair of oblique lateral incisions, terminal margin with prominent median cleft; maxilliped 2 without epipod.................. Pomatocheles Miers, 1879

— Penultimate segments of ocular peduncles each with reduced, narrow, calcified plate ( Fig. 3g, h ); telson with or without pair of oblique lateral incisions, but never prominent, terminal margin with or without median cleft; maxilliped 2 with epipod ( Fig. 4o).....................5

5. Shield as long as broad; rostral spine short, without accessory ventral spine; ultimate segments of ocular peduncles spinose, conical and tapered ( Fig. 3g ); telson rectangular, longer than broad, with pair of faint, oblique, lateral grooves, terminal margin with slight median notch........................... Parapylocheles Alcock, 1901

— Shield broader than long; rostrum very prominent, with accessory ventral subdistal spine; ultimate segments of ocular peduncles unarmed, basally swollen ( Fig. 3h ); telson subquadrate, slightly broader than long, without pair of faint, oblique, lateral grooves, terminal margin entire......................... Cancellocheles Forest, 1987

6. Abdominal somites, pleopods 3–5, and uropods symmetrical; telson subrectangular, longer than broad, usually with transverse line of flexion delimiting rounded posterior lobes ( Fig. 5b ); maxilliped 3 without epipod ( Fig. 4q)......................... Trizochele s Forest, 1987

— Abdominal somites, pleopods 3–5, and uropods asymmetrical; telson variable; maxilliped 3 with epipod ( Fig. 4p)............. Mixtopagurus A. Milne-Edwards, 1880

Figures

Figure 3. Basic morphology: a, diagrammatic pagurid (whole animal, dorsal view); b, diagrammatic lithodid (whole animal, dorsal view). Cephalothorax or shield, with or without cephalic appendages: c–h Pylochelidae; i, Diogenidae; j, Pylojacquesidae; k–m Paguridae. c, Pylocheles; d, Trizocheles; e, Cheiroplatea; f, Pomatocheles; g, Parapylocheles; h, Cancellocheles; i, Diogenes; j, Pylojacquesia; k, Porcellanopagurus; l, Solitariopagurus; m, Hemipagurus. Abbreviations: aa = antennal acicle; ant. = antenna; antu = antennule; c, cornea; car = carpus; cg = cervical groove; dac = dactyl; ff = fixed finger; irp = intercalary rostral process; la = linea anomurica; lf ch = left cheliped; lf ur = left uropod; lp = lateral projection; lt = linea transversalis; mer = merus; oa = ocular acicle; op = ocular peduncle; P2–5 = pereopods 2–5; pcl = posterior carapace lobe; pcme = posterior carapace median element; pl3–5 = pleopods 3–5; plm = palm; pmp = posterior median plate; pop = postocular projection; pro = propodus; r = rostrum or rostral lobe; rt ch = right cheliped; s = shield; sl1–3 = shield lobes 1–3; t6 = abdominal tergite 6; tel = telson. [a, b, adapted from Sandberg and McLaughlin, 1998; c, d from Forest et al. 2000; e–h, from Forest, 1987; i, from McLaughlin and Clark, 1997; j, from McLaughlin and Lemaitre, 2001c; k, l, from McLaughlin, 2000; m, from McLaughlin, 1997 (as Catapagurus); not to scale.]

Figure 5. Representative telsons: a, b, Pylochelidae; c–j, Paguridae; k, Parapaguridae. Sixth abdominal tergite, protopods of uropods and telson: j, Munidopagurus. Dactyl and propodus of pereopod 4: l, o, simple; m, q, subchelate; n, r, semichelate with multiple rows of corneous scales in propodal rasp and no preungual process; p, u, t, semichelate with single row of corneous scales in propodal rasp and preungual process at base of claw; s, semichelate with multiple rows of corneous scales in propodal rasp and preungual process at base of claw; t, chelate; v, semichelate with “type A” (cf. McLaughlin, 1974) sensory structure on lateral face of dactyl. Dactyl and propodus of pereopod 5: w, x subchelate; y, semichelate; z, chelate. [a, b, n, from Forest and McLaughlin, 2000; c, from Lewinsohn, 1982; d, e, from McLaughlin, 1982; f–i from McLaughlin, 1997; j, adapted from Provenzano, 1971; k, from Lemaitre, 1996; l, o–q, s, u, y, from McLaughlin, 1997; m, from McLaughlin and Lemaitre, 1997; q, w, from McLaughlin and Lemaitre, 2001c, v, from McLaughlin, 1974; x, after Lemaitre, 1998; not to scale].