Pedicelliops capillifer gen. et sp. nov., by present designation.

Larva. This new genus is distinguished by the combination of the following characters: A) body elongate and slender, head clearly hypognathous (Figs 1, 2); B) base of antennae close to each other, with carina between them (Fig. 2d); C) antenna shorter than head length, with strong bilateral enlargement of pedicellus (Fig. 3a); D) labrum small and rectangular, distal margin with medial emargination and small, square process, dorsal surface with long, stout, simple setae, erratically distributed in distal part, not arranged in one arc (Fig. 4a); E) right mandible with a stick-like, apically denticulate prostheca and a brush of short, fine setae between prostheca and mola (Fig. 4b, c); F) left mandible with a robust prostheca, apically with a comb-shaped structure and with a brush of short, fine setae between prostheca and mola (Fig. 4d, e); G) hypopharynx with medial tuft of stout setae (Fig. 4g); H) maxillary palp 2-segmented (Fig. 4h); I) glossae basally broad, narrowing toward apex, slightly shorter than paraglossae, ventrolateral margin with a row of short, thin setae and a row of long, simple setae close to margin, apically with some robust, long, curved setae; stout paraglossae with convex outer margin and apex, ventrolateral margin with a row of long, simple setae; labial palps segment II with distolateral protuberance, directed distally, segment III conical (Fig. 4i, j); J) legs with many long, simple setae on margins and on both surfaces of femur, femoral patch absent on all legs, patellotibial suture absent on foreleg and present on middle and hind legs, claw robust and pointed, with two rows of denticles (Figs 5, 6); K) fore protoptera with a protuberance near inner margin (Fig. 2a, b); L) posterior margin of abdominal tergites I–VIII smooth without spines (Fig. 1a).

Imagines. Unknown.

Pedicelliops is an arbitrary combination of letters with allusion to the Latin pedicellus and the Greek iops. Pedicellus is with reference to the striking second segment of the antennae and iops with reference to the Baetidae which look and move like small fishes. The gender is masculine.

Larva. (Figs 1–6).

Body. Elongate and slender, head hypognathous (Figs 1, 2).

Head. Antenna (Figs 3a, b, 2c, d) shorter than head length with strong bilateral enlargement of pedicellus. Antennae bases in close proximity to each other, with small carina between them.

Labrum (Fig. 4a). Small in comparison to other mouthparts, rectangular, wider than long; dorsal surface with long, stout, simple setae, erratically distributed in distal part, not arranged in one arc; ventrally with marginal row of setae composed of anterolateral long, simple setae and medial long, bifid setae.

Right mandible (Fig. 4b, c). Incisor and kinetodontium fused, both with well-developed denticles; inner margin of innermost denticle without a row of thin setae; prostheca stick-like, apically denticulate; margin between prostheca and mola with a brush of abundant, short, fine setae.

Left mandible (Fig. 4d–f). Incisor and kinetodontium fused, both with well-developed denticles; prostheca robust, apically with comb-shaped structure; margin between prostheca and mola with a brush of abundant, short, fine setae.

Hypopharynx (Fig. 4g). With a dorsomedial tuft of stout setae on lingua.

Maxilla (Fig. 4h). Apically with three stout canines and three denti-setae; distal denti-seta tooth-like, following same direction as canines, other denti-setae slender, bifid and pectinate; maxillary palp with two segments.

Labium (Fig. 4i, j). Glossae basally broad, narrowing toward apex, slightly shorter than paraglossae; ventrolateral margin with a row of short, thin setae and a row of long, simple setae close to inner margin, apically with some robust, long, curved setae. Paraglossae with convex outer margin and apex; ventrolateral margin with a row of long, simple setae; apical margin with three rows of long, stout setae (Fig. 4j). Labial palps segment II with distolateral protuberance, segment III conical.

Thorax. Fore protoptera (Fig. 2a, b). With a protuberance near inner margin.

Hind protoptera. Absent.

Foreleg (Figs 5a–c, 6a). Femur with many long, simple setae on dorsal and ventral margins and on both lateral surfaces; femoral patch absent; apex of femur with ventral lobe poorly developed; patellotibial suture absent; claw robust and pointed, with two divergent rows of denticles.

Middle and hind legs (Figs 5d–f, 6b, c). More slender than foreleg; femur with same setation as foreleg; femoral patch absent; anterior outer projection of femur apex directed towards the inner side of femur (Fig. 5d); patellotibial suture present; claw as in foreleg.

Abdomen. Tergites. Posterior margin of segments I–VIII smooth, without spines.

Gills (Fig. 3c, d). Seven pairs of gills on segments I–VII, dorsally oriented.

Paraproct (Fig. 3e). Without prolongation at posterior margin, with stout, marginal spines; cercotractor with few minute, marginal spines.

Caudal filaments (Fig. 1a, d). Inner margin of cerci with 2– 18 long, thin setae per segment, increasing in number distally; paracercus bilaterally with 3 to more than 12 long, thin setae per segment, increasing in number distally. Paracercus not reduced, but broken.

Imagines. Unknown.

(Fig. 7). West Africa: Guinea.

Larva. As the genus is monospecific, it is difficult to propose a relevant specific diagnosis. We can presume specific differences in the shape of the labial and maxillary palps, and in the setation of the forefemur. Species with less derived characters (shape of the pedicel, reduction of the labrum) may also be expected.

With reference to the remarkable setation found ventrally on the glossae and paraglossae, and on the femora.

Holotype. Guinea • larva; Bas. Niger, River Niandan, Loc. Sassambaya; ca. 400 m; 25.i.1985; leg. J.-M. Elouard; on slides; GBIFCH 00592365, GBIFCH 00592366; thorax and abdomen in alcohol; GBIFCH 00515518; MZL. Paratype. Guinea • larva; Boussoulé, Milo River; ca. 360 m; 14.iv.1987; leg. J.-M. Elouard; on slides; GBIFCH 00592319, GBIFCH 00592320; MZL.

Larva. (Figs 1–6). Body length 5.2 mm.

Colouration (Fig. 1a–d). Colouration strongly altered due to long term storage of the larvae in alcohol, with the cuticle becoming transparent. Head, thorax and abdomen dorsally brown, fore protoptera ecru. Head, thorax and abdomen light brown ventrally. Legs and caudalii light brown.

Head. Antenna (Fig. 3a, b). Short, ca. 2/3 of head length. Pedicellus bilaterally strongly enlarged and distally elongate on both sides. Scapus and pedicellus laterally with ovoid scales.

Labrum (Fig. 4a). Length 0.6× maximum width. Distal margin with medial emargination and a small, square process. Dorsal surface with long, stout, simple setae, erratically distributed in distal part, not arranged in one arc. Ventrally with marginal row of setae composed of anterolateral long, simple setae and medial long, bifid setae. Ventral surface with ca. three short, spine-like setae near lateral margin.

Right mandible (Fig. 4b, c). Incisor with four denticles; kinetodontium with three denticles. Margin between prostheca and mola straight; with setae along whole margin from prostheca to mola, shorter than 1/5 of prostheca. Tuft of setae present at apex of mola.

Left mandible (Fig. 4d–f). Incisor with five denticles; kinetodontium with three denticles. Margin between prostheca and mola straight; with setae along whole margin, shorter than 1/5 of prostheca, and a minute denticle toward subtriangular process. Subtriangular process long and slender, above level of area between prostheca and mola. Tuft of setae present at apex of mola.

Both mandibles with lateral margins convex. Basal half laterally with small, spatulate setae.

Hypopharynx and superlinguae (Fig. 4g). Lingua longer than wide and longer than superlinguae; with well-developed medial tuft of stout setae. Superlinguae distally rounded, lateral margins straight; long, fine, simple setae along distal margin.

Maxilla (Fig. 4h). Galea-lacinia ventrally with two simple, apical setae under canines. Medially with one spine-like seta and two short, simple setae. Maxillary palp ca. 1.3× as long as length of galea-lacinia; palp segment II 1.3× length of segment I; segment I widening in distal part; short, fine, simple setae scattered over distal part of surface of segment II; segment I laterally with short, robust setae; apex of segment II laterally pointed.

Labium (Fig. 4i, j). Inner margin of glossa with a row of short, fine, simple setae; ventral surface with a row of long, fine, simple setae close to margin; apex with six long, robust setae, curved toward inner side, and two shorter, spine-like setae; outer margin bare. Paraglossa with outer margin and apex convex and inner margin concave, slightly curved inward; ventrally with three rows of long, robust setae in apical area, four short, fine, simple setae in anteromedial area and a row of four long, simple setae on margin; dorsally with a row of six long, spine-like setae near inner margin. Labial palp with segment I 0.9× length of segments II and III combined. Segment I with few short, fine, simple setae ventrally. Segment II with slender, distolateral protuberance, directed distad; distomedial protuberance 0.3× width of base of segment III; ventral surface with short, fine, simple setae; dorsally without spine-like setae near outer margin. Segment III conical; length 0.8× width; ventrally covered with short, spine-like setae and short, fine, simple setae.

Thorax. Fore protoptera (Fig. 2a, b). With a protuberance near inner margin.

Hind protoptera. Absent.

Foreleg (Figs 5a–c, 6a). Ratio of foreleg segments 1.4: 1.0: 0.8: 0.4. Femur. Broad, length ca. 2× maximum width. With many long, simple setae on dorsal and ventral margins as well as on anterior and posterior surface; length of setae mostly ca. 0.6× maximum width of femur; femoral patch absent. Tibia. Dorsal margin bare; with a row of medium, spine-like setae along ventral margin; one medium, spine-like seta at distomedial margin. Patellotibial suture absent. Tarsus. Dorsal and ventral margins bare, with short to medium, spine-like setae scattered over surface. Claw robust and distally pointed, with two divergent rows of denticles; denticles with different sizes, two apical denticles clearly larger than other denticles; subapical setae absent (Fig. 2b).

Middle and hind leg (Figs 5d, e, 6b, c). Ratio of middle and hind leg segments 1.2: 1.0: 0.6: 0.3. Femur. Length ca. 3× maximum width. With same setation as foreleg; femoral patch absent. Tibia. Dorsal margin bare. Ventral margin margin with a row of short, spine-like setae. Patellotibial suture present on basal ½ area. Tarsus. Dorsal margin bare. Ventral margin with a row of short, spine-like setae. Claw as foreleg.

Abdomen. Gills (Fig. 3c, d). Seven pairs of gills on segments I–VII. Margin undulated, with short, stout, curved setae. Tracheae partly extending from main trunk to inner and outer margins. Gill I as long as the length of segments II and 2/3 of III combined. Gills II–VII unknown.

Paraproct (Fig. 3e). With nine stout, marginal spines. Surface scattered with micropores. Cercotractor with convex margin and a few minute, marginal spines.

West Africa: Guinea (Fig. 7).