Cincticostella bifurcata, Xie, Hui, Jia, Yan-Yan, Chen, Ping, Jacobus, Luke M. & Zhou, Chang-Fa, 2009

Xie, Hui, Jia, Yan-Yan, Chen, Ping, Jacobus, Luke M. & Zhou, Chang-Fa, 2009, Two new Cincticostella species from China with a larval key to species of the genus (Ephemeroptera: Ephemerellidae), Zootaxa 2299, pp. 53-61 : 58-60

Key to the known species of the genus Cincticostella (mature larva, larval stage of C. indica has not been reported so far)

1. Middle and hind femora expanded and usually somewhat serrate (figs. 1, 17, 20, 22, 23) ......................................... 2

1’. Middle and hind femora not significantly expanded (figs. 19, 21, 24, 25)................................................................... 5

2. Abdominal tergal spines on segments 5-8 bifurcate (figs. 1, 12, 13, 22) ........................................ C. bifurcata sp.nov.

2’. Abdominal tergal spines on 5-8 not bifurcate............................................................................................................... 3

3. Midfemur with deep, U-shaped, apical notch at joint with tibia (fig. 23) .................................................................... 4

3’. Midfemur without such notch (fig. 28)........................................................................................................ C. braaschi

4. Pronotum greatly expanded around head capsule (figs. 17, 23) .................................................................. C. femorata

4’. Pronotum not extremely expanded (figs. 20, 26) ............................................................................................ C. insolta

5. Maxillary palp present, sometimes vestigial (see figs. 6, 16)....................................................................................... 6

5’. Maxillary palp absent......................................................................................................................................... C. gosei

6. Maxilla with crown expanded and flattened (fig. 16)................................................................................................... 7

6’. Maxilla with crown only slightly expanded and not flattened...................................................................................... 8 22, C. bifurcata sp. nov.; 23, C. femorata ; 24, C. fusca ; 25, C. gosei ; 26, C. insolta ; 27, C. nigra .

7. Mesal plate with paired ridges or projections on posterior margin; median filament length subequal to length of abdomen ...................................................................................................................................................... C. orientalis

7’. Mesal plate without such ridges or projections; median filament length much greater than length of abdomen .......... .................................................................................................................................................................. C. corpulenta

8. Anterolateral projections of mesothorax notched medially, sometimes with sharply pointed appearance (fig. 15) .... 9

8’. Anterolateral projections of mesothorax blunt and not notched, with margins usually subparallel to lateral aspect of body............................................................................................................................................................................. 11

9. Abdominal terga with paired spines on posterior margins ......................................................................................... 10

9’. Abdominal terga without such spines ..................................................................................... C. szechuanensis sp.nov.

10. Setae on lateral margins of abdominal segments numerically reduced, stout and spinelike; longitudinal stripes absent from abdominal terga; and median filament length nearly subequal to length of abdomen .............................. C. fusca

10’. Setae on lateral margins of abdominal segments numerous and generally spatulate; distinct longitudinal stripes usu- ally present on abdominal terga; and median filament length greater than length of abdomen ............. C. levanidovae

11. Genae expanded and angulate ......................................................................................................................... C.colossa

11’. Genae rounded ............................................................................................................................................................ 12

12. Upper surface of femora densely covered with short, clavate setae .......................................................... C.elongatula

12’. Upper surface of femora smooth, without short, clavate setae .......................................................................... C. nigra