Lepidocyrtus (Fractocyrtus), Cipola & Bellini, 2018

Subgenus Fractocyrtus Cipola & Bellini, 2018 View in CoL

Type species: Lepidocyrtus amazonaensis Cipola nom. nov. (Fig. 2 View FIGURE )

Diagnosis of subgenus. Antennae, legs (except coxae II–III) and collophore without scales. Antennae shorter than body length (Figs 2 View FIGURE , 6 View FIGURE 6 , 13); Ant IV not annulated and without apical bulb. Four ciliate prelabral chaetae ( Figs 3A View FIGURE 3 ). Th II slightly projected over the head anteriorly (Figs 2, 6, 13). Th II, Th III and Abd IV (laterally) polychaetotic, covered by numerous small ciliated mic interspersed among scales ( Figs 15A View FIGURE 15 , 16B View FIGURE 16 ). Abd III laterally with a tuff of elongated chaetae ( Figs 9A View FIGURE 9 , 16A View FIGURE 16 ). Body psp pattern ( Figs 4–5 View FIGURE 4 View FIGURE 5 , 10 View FIGURE 10 , 17 View FIGURE 17 ): anteriorly to eyepatches (0), clypeus inner (2), Th II–Abd IV (1), coxae I–III (2, 4, 2), proximal manubrium (1), manubrial plate (2) and proximal dens (6–7); lateral psp: Th III–Abd III (0), BP4 variable; ventral psp: as Ant III (1), Ant II (1, rarely 5), Ant I (0), Th I–III (1), collophore anteriorly (1) and posteriorly (1), between collophore and tenaculum (1), tenaculum posteriorly variable, Abd IV (0) and anterior to genital plate (1 unpaired). Unguiculus inner lamella excavate ( Figs 3B View FIGURE 3 , 11E View FIGURE 11 ). Dens dorsally with at least 10 proximal ciliate spines and a large, apically truncate dental tubercle ( Figs 3C View FIGURE 3 , 12C View FIGURE 12 , 18F View FIGURE 18 ). Mucronal spine with small basal spinelet ( Fig. 12D View FIGURE 12 ).

The following characters are shared in four Fractocyrtus species known:

Habitus typical of Lepidocyrtinae (Figs 2, 6, 13); brownish scales weakly ciliate, oval, elongated or pyriform (rarely) and apically rounded, truncate or irregular unilaterally or bilaterally (rarely) present on all head, thorax, abdomen, coxae II–III ( lapsus as “absent” in L. ( F.) mateosi in Cipola et al. 2018b), and manubrium and dens ventrally (Figs 2, 6, 7E, 11B–C, 12B).

Head. Ant I–IV with numerous finger-shape sens and ciliate chaetae; Ant I dorsally with 3 proximal sens-like smooth chaetae (Ant I organ sensu Ḩther 1986) ( Figs 7B View FIGURE 7 , 14B View FIGURE 14 ). Eyes 8 per side with 5 interocular chaetae ( q, v, p, r, t); eyepatches posterior region with 1 bothriotrichum ( Pa6) ( Figs 7B View FIGURE 7 , 14B View FIGURE 14 ). Four prelabral chaetae ( pl1–2) ciliated and subequals ( Fig. 3A View FIGURE 3 , 7C View FIGURE 7 ). Labral formula with 4 ( a1–2), 5 ( m0–2), 5 ( p0–2) smooth chaetae, a1 moderately thicker, p0–2 largest, others subequals ( Fig. 3A View FIGURE 3 ). Labral papilla absent ( lapsus as “present” in Cipola et al. 2018b) ( Fig. 3A View FIGURE 3 ). Maxillary palp with smooth t.a. and b.c.; sublobal plate with 1 minute distal appendix ( s.b.4) and 3 inner appendages ( s.b.1–3) smooth and subequals ( Fig. 3A View FIGURE 3 ). Labial palp with 5 main papillae (A–E) plus 1 hypostomal papilla (H), with 0, 5, 0, 4, 4, 2 guard appendages, respectively ( Fig. 3A View FIGURE 3 ); papilla E l.p. reduced ( Figs 7D View FIGURE 7 , 14D View FIGURE 14 ). Labial palp with 5 subequal smooth p.c.; basolateral and basomedian labial fields with chaetae a1–5 smooth on anterior row ( a2 largest), M2, E and L1–2 ciliate ( M1 absent), r reduced to a spine-like mic ( Figs 7E View FIGURE 7 , 14E View FIGURE 14 ).

Dorsal trunk chaetotaxy. Th II–Abd IV macrochaetotaxy formula with 0, 0| 0, 1+1, 0, 2 mac; Th II–Abd V with ms and sens formula 1,0|1,0,1,0,0 and 1, 1| 0,1, 1,+,3, respectively ( Figs 8–9 View FIGURE 8 View FIGURE 9 , 15–16 View FIGURE 15 View FIGURE 16 ). Abd II–IV bothriotrichal formula 2 ( a5, m2), 3 ( a5, m2, m5), 2 ( T2, T4) ( Figs 8D View FIGURE 8 – 9B View FIGURE 9 , 15D View FIGURE 15 – 16B View FIGURE 16 ).

Legs. Tibiotarsus I–III outer side distally with 1 tenent hair finely ciliate and apically capitate, inner side of tibiotarsus III with 1 smooth chaeta ( Fig. 3B View FIGURE 3 ). Pretarsus with one anterior and one posterior small chaeta ( Fig. 11E View FIGURE 11 ). Unguis I–III outer side with 2 paired lateral teeth and 1 unpaired proximal medial tooth; inner edge with 4 teeth, 2 paired b.t., 1 unpaired m.t. subequal to b.t. and 1 unpaired a.t. slightly smaller; unguis I–II b.t. on proximal fifth, m.t. on proximal half and a.t. on distal fifth; unguis III b.t. on a little less than proximal half, m.t. on proximal third and a.t. on distal sixth ( Figs 3B View FIGURE 3 , 11E View FIGURE 11 ). Unguiculus I–III with 4 lamellae ( ai, ae, pi, pe) acuminate and smooth, except pe serrate and ai weakly excavate ( lapsus as “truncate” in Cipola et al. 2018b) strongly on I–II and less on III ( Figs 3B View FIGURE 3 , 11E View FIGURE 11 ).

Furcula. Manubrium ventrally with 3 inner ciliate chaetae, 1 outer chaeta somewhat larger (as “subequal” in L. ( F.) mateosi in Cipola et al. 2018b) than the others ( Figs 12B View FIGURE 12 , 18F View FIGURE 18 ). Dens dorsally with a large, apically truncate dental tubercle ( Figs 3C View FIGURE 3 , 12C View FIGURE 12 ); ventral side distally with at least 1 lanceolate ciliate chaeta ( Fig. 12D View FIGURE 12 ). Mucro bidentate with distal tooth larger than proximal tooth, mucronal spine surpassing apex of proximal tooth and with 1 small basal spinelet ( Fig. 12D View FIGURE 12 ).