Lyreidinae Guinot, 1993

Van Bakel, Barry W. M., Guinot, Danièle, Artal, Pedro, Fraaije, René H. B. & Jagt, John W. M., 2012, A revision of the Palaeocorystoidea and the phylogeny of raninoidian crabs (Crustacea, Decapoda, Brachyura, Podotremata) 3215, Zootaxa 3215 (1), pp. 1-216 : 77-78

Subfamily Lyreidinae Guinot, 1993

Lyreidinae Guinot, 1993b: 1326 .

Type genus. Lyreidus De Haan, 1841 .

Genera included. Bournelyreidus n. gen., Heus Bishop & Williams, 2000 , Lyreidus De Haan, 1841 , Lysirude Goeke, 1986 , Macroacaena Tucker, 1998 , and Rogueus Berglund & Feldmann, 1989 .

Diagnosis. Carapace longer than wide, elongated, generally narrow, pyriform or fusiform, with long, narrow anterior portion, or with wide, sinuous anterior margin. Anterolateral margin lacking tooth or with 1 or 2 teeth, with long spine ( Lysirude , Macroacaena ) or single, strong bifurcated spine ( Rogueus ). Posterolateral margin long, generally rimmed. Posterior margin short, concave. Cervical groove absent; branchiocardiac groove short. Carapace smooth, regions indistinct; cuticle microstructure with pits and upright nodes. Rostrum broadly triangular or subtrapezoidal. Orbitofrontal margin from narrow, less than one-third of maximum carapace width, to wide, threequarters of maximum carapace width. Supraorbital margin generally unarmed, with single fissure, or with few teeth ( Macroacaena ). Antennules, antennae about same size and general shape; long, slender, modified in connection with respiratory currents. Antennule not folded, basal article expanded, somewhat concave internally so that when apposed both antennules form conduit for the exhalant current. Proepistome narrow. Epistome anteriorly produced between basal articles of antennules. Subantennary lobe of pterygostome developed, produced far in front of mandibles, fused over a long stretch with epistome edges. Mxp3 long, narrow, slender, oxystomian condition; merus longer than ischium. Milne-Edwards openings absent. Pterygostome elongated, non-areolated, tumid. Pleurites 5‒7 partially exposed, not excavated, forming flat area, not overhung by edge of branchiostegite. Sternum/pterygostome junction moderately developed; junction sternum/pleurites well developed between P1, P2, less so between P2, P3. Thoracic sternum long, narrow, strongly deflected behind sternite 7; sternite 3 variously crown shaped; sternite 4 not much expanded, flat; sutures 4/5 reduced, crescent shaped; sternite 5 relatively wide; sternite 6 only slightly narrower; sternite 7 narrowing posteriorly; sternite 8 narrow, elongated, perpendicular to preceding ones. Medial line along sternites 7, 8.

Pair of strong, elongated, hook-like projections arise from episternite 5, recurved at tip, distally with double peg that firmly fits into pair of deep sockets in latero-posterior extended corners of abdominal somite 6; locking may be effective in ovigerous females, even with large egg mass, but becoming obsolete in larger females. Socket on abdominal somite 6 long, limited by thickening.

Two small spermathecal apertures face each other on opposite sides of depression (sunken pit) on sternite 7, separated by vertical medial wall, marked externally by medial line.

Chelipeds homochelous, homodontous. Basis-ischium immoveably fused with long merus. Propodus of variable length, flattened; its upper margin unarmed or with single spine; lower margin armed with few sharp spines; dactylus long, smooth on dorsal border, bent against anterior border of palm; fixed finger much inflated; prehensile borders of both fingers with staggered, low teeth.

P2‒P4 rather slender. Merus rather long, slender. Propodus, dactylus flattened, compressed. P2 propodus short, broad, dactylus slightly spatulate. P3 propodus longer, dactylus elongated, styliform, externally ridged. P4 carpus, propodus, dactylus variously lobate. P4 coxae subdorsally located. P5 more dorsal, much reduced, filiform, ending in small, flattened, elliptical dactylus.

Sterno-abdominal depression present posteriorly, entirely covered by male abdomen. Abdomen freely articulated (6 articles plus small telson), narrow, fixed; somites 1‒3 dorsal, in straight line with carapace, rest completely folded; sharp flexure at level of somite 4 which bears a strong spine; somite 5 may also bear single spine; somite 6 longer, ventrally with developed sockets fitting double peg of the hook-like projections of thoracic sternite 5 for abdominal locking mechanism. Sexual dimorphism indistinct. Posterior branchial orifices or water conduits on the flanks of carapace absent; instead, with post-frontal modifications for respiratory current.