Four new species of Callibaetis Eaton (Ephemeroptera: Baetidae), nymphal description of Callibaetis (Abaetetuba) fasciatus (Pictet) and keys for South American species of Callibaetis Cruz, Paulo Vilela Salles, Frederico Falcão Hamada, Neusa Zootaxa 2017 4250 3 229 261 3FCJ 172518 [679,808,571,597] Insecta Baetidae Callibaetis Animalia Ephemeroptera 29 258 Arthropoda genus    1. Forewing with single marginal intercalary vein.............................................................. 2  1’. Forewing with paired marginal intercalary veins.............................................................4   2. Forceps segment III with apex rounded ( Fig. 10G in Cruz et al.2017), brownish specimens (before fixation) ( Fig. 10A in Cruz et al.2017)...............................................................................  C.( Ab.) pollens  2’. Forceps segment III with apex truncated ( Fig. 11C in Cruz et al.2014), green specimens (before fixation) ( Fig. 11D in Cruz et al.2014)............................................................................................3   3. Turbinate portion of compound eyes with stalk height 0.4–0.5× dorsal portion height ( Fig. 11B in Cruz et al.2014), costal pro- cess of hind wing rounded ( Fig. 11F in Cruz et al.2014).........................................  C.( Ca.) gonzalezi  3’. Turbinate portion of compound eyes with stalk height 0.85–0.90× dorsal portion height (Fig. 26B in Cruz et al.2014), costal process of hind wing quadrangular (Fig. 26E in Cruz et al.2014)...................................  C.( Ca.) radiatus   4. Dorsal surface of turbinate portion of compound eyes rounded ( Fig. 10A in Cruz et al.2014).........................5  4’. Dorsal surface of turbinate portion of compound eyes oval ( Figs 5A, 13A)........................................ 6   5. Turbinate portion of compound eyes with constriction on apical third ( Fig. 10B in Cruz et al.2014)........  C.( Cu.) gelidus  5’. Turbinate portion of compound eyes with constriction on basal third ( Fig. 21B in Cruz et al.2014)......  C.( Cu.) nigracyclus   6. Abdominal terga III, V and VII with oblique red mark ( Figs 7A and 22E in Cruz et al.2017)..........................7  6’. Abdominal terga III, V and VII without oblique red mark ( Fig. 2A in Cruz et al.2017)............................. 11   7. Abdominal sterna with one medial mark on anterior margin ( Fig. 11G in Cruz et al.2017)...............  C.( Ca.) willineri  7’. Abdominal sterna without one medial mark on anterior margin ( Fig. 7B in Cruz et al.2017)..........................8   8. Turbinate portion of compound eyes (in lateral view) with anterior and posterior margins subparallel ( Fig. 2in Cruz et al.2009and Fig. 17B in Cruz et al.2014).........................................................................9  8’. Turbinate portion of compound eyes (in lateral view) with anterior and posterior margins divergent ( Fig. 13B, Fig. 1B in Cruz et al.2014)......................................................................................... 10   9. Turbinate portion of compound eyes with stalk height 1.9× dorsal portion height ( Fig. 17B in Cruz et al.2014), marginal inter- calary veins on hind wing present ( Fig. 17E in Cruz et al.2014)....................................  C.( Ca.) jocosus  9’. Turbinate portion of compound eyes with stalk height 2.6× dorsal portion height, marginal intercalary veins on hind wing absent ( Figs 4a and 4b in Cruz et al.2009)......................................................  C.( Ca.) zonalis   10. Turbinate portion of compound eyes with stalk height 1.1× dorsal portion height ( Fig. 1B in Cruz et al.2014).................................................................................................  C.( Cu.) calloventer  10’. Turbinate portion of compound eyes with stalk height 1.9× dorsal portion height......................  C.( Ca.) guttatus   11. Forewing without pigmentation (Fig. 29 in Cruz et al.2009and Fig. 13D in Cruz et al.2014)........................12  11’. Forewing with pigmentation ( Fig. 2in Nieto & Cruz 2013and Fig. 27D in Cruz et al.2014).........................14   12. Abdominal sterna with two large marks on anterior margin ( Fig. 2B in Cruz et al.2017)................  C.( Ab.) capixaba  12’. Abdominal sterna without two large marks on anterior margin ( Fig. 13C)........................................13   13. Abdominal sterna and terga with transverse small brown mark on posterior margin, abdomen without spots ( Figs 13F and 13Iin Cruz et al.2014).........................................................................  C.( Ai.) itannae  13’. Abdominal sterna and terga without small brown transverse mark on posterior margin, abdomen covered by spots ( Fig. 13A).................................................................................  C.( Ca.) molinerii  sp. nov.   14. Forewing with apical third completely pigmented, basal 2/3 hyaline ( Fig. 2in Nieto & Cruz 2013)......  C.( Ab.) dominguezi  14’. Forewing without apical third completely pigmented, basal 2/3 with some pigmentation.............................15   15. Forewing pigmentation forming bands ( Figs 5D and 27D in Cruz et al.2014).....................................16  15’. Forewing pigmentation not forming bands ( Figs 17D and 6B in Cruz et al.2014)..................................18   16. Apical band parallel to posterior margin of forewing (Fig. 27D in Cruz et al.2014)....................  C.( Ab.) sellacki  16’. Apical band transverse to posterior margin of forewing ( Fig. 9C in Cruz et al.2014)...............................17   17. First segment of forceps cylindrical ( Fig. 5C in Cruz et al.2014)...................................  C.( Ca.) cruentus  17’. First segment of forceps with base wider than apex ( Fig. 9F in Cruz et al.2014).......................  C.( Ab.) fasciatus   18. Pair of medioanterior and medioposterior sigilla on abdominal terga strong pigmented ( Fig. 11A).  C.( Cu.) imperator  sp. nov.  18’. Pair of medioanterior and medioposterior sigilla on abdominal terga without pigment ( Fig. 6E in Cruz et al.2017).......................................................................................................  C. jaffueli