Outlines of the calcareous rings: (17) Ypsilothuria bitentaculata attenuata (after Heding, 1942); (18) Ypsilothuria bitentaculata bitentaculata (MZUSP 1306); (19) Ypsilothuria bitentaculata virginiensis (after Heding, 1942). Note in 18 radials and interradials narrow and the anterior end of both radials and interradials deeply notched. R, radial plate. IR, interradial plate.

 
 
  Part of: Martins L, Tavares M (2018) Ypsilothuria bitentaculata bitentaculata (Echinodermata: Holothuroidea) from the southwestern Atlantic, with comments on its morphology. Zoologia 35: 1-6. https://doi.org/10.3897/zoologia.35.e24573