Identification key for World Caleidoscopsis species

1. Epimeral plate 3, posteroventral angle with a tooth; urosomite 1 with 1 dorsal tooth, small or long..................... 2

- Epimeral plate 3, posteroventral angle rounded, without a tooth; urosomite 1 with 2 small dorsal teeth, not reaching half-length of the urosomite 2..................................................... Caleidoscopsis tikal (J.L. Barnard, 1967)

2. Coxa 5 subtriangular, as long as wide; epimeral plate 3, posteroventral angle with moderate tooth, not exceeding end of urosomite 1.......................................................................................... 3

- Coxa 5 subrectangular, longer than wide; epimeral plate 3, posteroventral angle with a well-developed tooth, exceeding end of urosomite 1................................................... Caleidoscopsis simplignathia (J.L. Barnard, 1962)

3. Urosomite 1 not covering urosomite 2, with 1 small dorsal tooth; urosomite 2 with 1 small dorsal tooth, not exceeding halflength of urosomite 3.................................................................................. 4

- Urosomite 1 covering part of urosomite 2, with 1 long dorsal tooth; urosomite 2 with 1 very long dorsal tooth almost reaching the end of urosomite 3....................................................... Caleidoscopsis karamani sp. nov.

4. Antennae 1–2 flagellum with short articles, as long as wide; pereopod 7, basis 1.5x longer than wide; uropod 3, outer ramus with long article 2, about 40% of total length of ramus........................................................ 5

- Antennae 1–2 flagellum with long articles, at least 2x longer than wide; pereopod 7 basis thinner, 2x longer than wide; uropod 3, outer ramus with short article 2, about 25% of total length of the ramus......... Caleidoscopsis inermis (Ledoyer, 1986)

5. Antenna 1 simple, not geniculate; maxilliped palp, article 4 longer than 3; pereopods 5–7, propodus longer than dactylus...................................................................... Caleidoscopsis copal (J.L. Barnard, 1967)

- Antenna 1 geniculate, folded up; maxilliped palp article 4 shorter than 3; pereopods 5–7, propodus shorter than dactylus............................................................................... Caleidoscopsis carlosi sp. nov.