Diagnosis. Trunk elongate; lateral processes well separated; neck very short, usually with collar; chelifores and palps lacking in adults; ovigers in males only, seven-segmented, usually with vestigial strigilis-like spines sparsely distributed on the terminal segment, without terminal claw; legs long and slender, tarsus short, propodus long, with welldeveloped heel spines and strong auxiliary claw. Cement gland opening as many dorsal pores or tiny ducts arranged in one or two rows.
Remarks. Members of this genus mostly inhabit shallow waters, with several exceptions known to live on floating seaweeds; some species have been observed to swim (Morgan 1971; Isaac & Jarvis 1973; Clark & Carpenter 1977). Endeis is widely distributed except in polar regions; the genus has not been reported from the Arctic Ocean, and only two species, E. australis (Hodgson, 1907) and E. viridis Pushkin, 1976, have been reported from Antarctic waters (Fry & Hedgpeth 1969; Pushkin 1993). At present there are 17 known species worldwide, generally occurring in low abundance but locally abundant in some habitats. Despite its broad distribution, this genus is morphologically uniform, though highly derived.
Most species of Endeis have been recorded from relatively warm waters. The three species previously known from Japanese waters, E. mollis (Carpenter, 1904), E. nodosa Hilton, 1942, and E. meridionalis (Böhm, 1879), have been collected south of 35 ° N. Of these, we did not find E. mollis and E. nodosa in our survey, though they are known from the Nansei Islands. Ohshima (1935) collected Endeis mollis from the Ishigaki Islands as the first Endeis recorded from Japan. Nakamura and Child (1983, 1988) subsequently recorded this species from Sagami Bay and Iriomote Island, and Nakamura and Child (1988) reported Endeis nodosa from Naha Bay. Utinomi (1971) reported Endeis meridionalis from Chijiwa Bay, Nagasaki; this species has an equatorial distribution in the Indian Ocean, western Atlantic Ocean, and western Pacific Ocean, with Nagasaki the northern limit of its range.