Psammonella Glazaczow 1987

Subgenus Psammonella Glazaczow 1987

( Figs 97–189 View FIGURES 94–97 View FIGURES 98–102 View FIGURES 103–108 View FIGURES 109 View FIGURES 110–116 View FIGURES 117–122 View FIGURES 123–131 View FIGURES 132–135 View FIGURES 136–143 View FIGURES 144–150 View FIGURES 151–154 View FIGURES 155–158 View FIGURES 159–164 View FIGURES 165–173 View FIGURES 174–180 View FIGURES 181–189 )

Psammonella Glazaczow (in Jacob & Glazaczow) 1987: 203.

Type species: Pseudocentroptiloides ( Psammonella) ceylonica Glazaczow (in Jacob & Glazaczow) 1987.

Autapomorphy of Psammonella. Maxilla, being shortened (as in Pseudocentroptiloides View in CoL s. str.), is apically armed with 3 transverse crests—two transverse crests formed by setae, and a shorter lamellate transverse crest between them ( Figs 27–31 View FIGURES 25–28 View FIGURES 29–31 ).

The transverse setal crest laterad of canines ( l.s.cr) represents a very dense and regular row of long, stout, hooked setae, which are projected distad of other two crests ( Fig. 30 View FIGURES 29–31 ); corresponding crest is present in Pseudocentroptiloides View in CoL s. str. ( Figs 25, 26 View FIGURES 25–28 ); in other taxa setae corresponding to this crest are few and small ( Fig. 194 View FIGURES 190–197 ).

The transverse crest formed by fused canines ( can.cr) is integral and plate-like, with convex lateral surface and concave median surface ( Fig. 27 View FIGURES 25–28 ); it corresponds to three separate canines, which are shortened in Pseudocentroptiloides View in CoL s. str. ( Figs 25–26 View FIGURES 25–28 ) and are long in most other Procloeon View in CoL ( Fig. 194 View FIGURES 190–197 ).

The transverse setal crest mediad of canines ( m.s.cr) is a unique formation not found in other mayflies. It represents a distal continuation of the longitudinal medio-ventral row of setae which is sharply bent in dorsal direction, changing its orientation from longitudinal to transverse one ( Figs 28–29 View FIGURES 25–28 View FIGURES 29–31 ). Setae forming this crest are longer than the plate-like crest formed by fused canines, and are curved S-sharply, so that are partly inserted into the concavity of the plate-like crest ( Fig. 27 View FIGURES 25–28 ). In all other mayflies the medio-ventral setal row, as well as the neighboring medio-dorsal setal row, is terminated close to canines, is not bent apically and does not form a transverse portion ( Figs 25–26 View FIGURES 25–28 ).

General characteristic of Psammonella. Labrum widened distally, with distal margin widely incised ( Figs 67 View FIGURES 67–73 , 117 View FIGURES 117–122 , 144 View FIGURES 144–150 , 165 View FIGURES 165–173 ) (the same in Pseudocentroptiloides View in CoL and Procloeon furcalabrum sp. nov.). Incisor and kinetodontium of each mandible separated nearly up to base ( Figs 72–73 View FIGURES 67–73 , 121–122 View FIGURES 117–122 , 145–146 View FIGURES 144–150 , 166–167 View FIGURES 165–173 ) (the same in Pseudocentroptiloides View in CoL , P. furcalabrum sp. nov. and P. macronyx View in CoL ). Maxillae modified (see above). Maxillary palp 2- or 3-segmented, or variable [as in other Procloeon View in CoL ( Figs 15–17 View FIGURES 9–24 )]. Hypopharynx apically widened and concave, with projection in middle of concavity, i.e. with 3 apices ( Figs 71 View FIGURES 67–73 , 118 View FIGURES 117–122 , 149 View FIGURES 144–150 , 170 View FIGURES 165–173 ). Glossae short and wide; paraglossae longer and narrower than glossae, arched, parallel-sided ( Figs 69–70 View FIGURES 67–73 , 119 View FIGURES 117–122 , 147–148 View FIGURES 144–150 , 173 View FIGURES 165–173 ). Hind wings of winged stages and hind protoptera of larvae completely absent in all known species ( Figs 65 View FIGURES 60–66 , 113 View FIGURES 110–116 , 139 View FIGURES 136–143 ) (the same in many other Procloeon View in CoL ). Claws long and slender, without denticles ( Figs 74 View FIGURES 74–79 , 114–116 View FIGURES 110–116 , 151–153 View FIGURES 151–154 , 174–177 View FIGURES 174–180 ). Tergalii either with dorsal lamella ( Figs 46–49 View FIGURES 32–59 ), or without it ( Figs 32–45, 50–58 View FIGURES 32–59 ).