On the systematic position of Heloecius cordiformis
Males of Heloecius possess a coxo-sternal genital opening. This character suggests that Heloecius is the most primitive crab within the classical Ocypodidae. It is therefore excluded from the Ocypodinae and a new subfamily, the Heloecinae, is proposed for it. The relationships of this subfamily are discussed and Ucides, an American genus of mangrove crab, is provisionally included in the new subfamily.