Key to the species of Neocrangon Zarenkov, 1965

1. Eyes very large, diameter more than 0.3 times of carapace length ............................... N. abyssorum (Rathbun, 1902) (northern Pacific from southern California to Pacific coast of Hokkaido, Japan; 887–4000 meters)

- Eyes moderate in size, diameter less than 0.3 times of carapace length....................................................................... 2

2. Body surface with pubescence...................................................................................................................................... 3

- Body surface naked....................................................................................................................................................... 4

3. Distance between anterior dorsomedian spine of carapace and tip of rostrum more than twice of distance between anterior dorsomedian spine and posterior dorsomedian spine ........................................ N. communis (Rathbun, 1899) (Berling Sea to San Diego, California; 16–565 meters)

- Anterior dorsomedian spine situated at about middle from posterior dorsomedian spine to tip of rostrum .................. ........................................................................................... N. joloensis (De Man, 1929) (off Jolo Island, Philippines)

4. Rostrum with pronounced dorsal sulcus, apex blunt; pleuron of fourth pleomere with posterolateral spine, pleuron of fifth with posterolateral angle pointed ................................................................................. N. resima (Rathbun, 1902) (From off San Francisco, California, to San Domingo Point, Lower California; at depths of 27–487 meters)

- Rostrum with faint dorsal carina, apex acute; pleuron of fourth pleomere without posterolateral spine, fifth pleuron with posterolateral spine ............................................................................................................... N. orientalis sp. nov.