Mantle small, 25 cm in total length. Head narrow, constricted. Arm extraordinarily
long, with hectocotylized arm at the right Arm V in male. Lingula short,
with lingula index 1.8─2.5%. Half demibranchs 11. Grayish brown when fresh.
Distribution:
Caribbean Sea, off Suriname and the Mediterranean Sea.
Remarks:
The Mediterranean form is separated by Robson (1929) under the subspecific name, O. defilippi dama, because of slenderer mantle and arms.