Leucosia insularis

Takeda & Kurata, 1976

Carapace a little broader than long, convex and high in the middle, evenly sloping antero-laterally. Front moderately prominent, dorsally concave in its median line and defined dorso-laterally without distinct postorbital constriction; its free margin obscurely four-lobed. Hepatic region rather angulated, but very faintly demarcated dorsally. Antero-lateral and postero-lateral borders nearly equal in length; lateral angle of carapace expanded laterally to form a lobe overhanging the thoracic sinus; its free edge devoid of granules, only with a fringe of short stiff hairs; just behind this lateral lobe is a faint concavity, and then postero-lateral border strongly convergent posteriorly; thickened epimeral edge or true postero-lateral border visible in dorsal view throughout its extent and continuous with posterior border, being beaded with depressed granules without hairs.
Thoracic sinus deep, sharply defined anteriorly by smooth overhanging margin of pterygostomial region, containing many spongy hairs, a large, suboval truncated tubercle in front of coxa of cheliped, and a longitudinal line of several pearly granules below the overhanging edge of lateral lobe.
Chelipeds rather short and robust. Merus depressed and widens distally, its anterior upper border being armed with three large and two or three small pearly tubercles; its lower border and proximal part of anterior surface also covered with a cluster of round tubercles of good size; upper surface with two tubercles and a mat of short setae at its proximal end, and otherwise smooth and shining; posterior border beset with a row of several studded, depressed tubercles. Outer borders of palm and movable finger cristate and entire, while inner border of palm weakly swollen with a row of obscure granules distally; fingers about two-thirds the length of palm and obscurely dentate distally, a narrow hiatus being left proximally.
Ambulatory legs strong. Merus with one anterior and two posterior granulated crests; in first pair, in addition, a longitudinal one on upper surface along anterior crest. Anterior border of carpus and both borders of propodus strongly crested.
Abdomen fairly wide and consists of four pieces; first segment small, and lateral border of second sinuate with a distinct constriction at its subdistal part; third as long as second, with a small transverse plate near its median part, regularly tapering distally.
No distinct ocelli, and dorsum only mottled with brownish stripes which are indistinct, but symmetrically disposed and more or less reticulated. Similar stripes on chelipeds. (Takeda & Kurata, 1976b)

Type locality: Wanto-ne, coral fishing ground between Chichi-jima and Haha-jima, Ogasawara-shoto, Japan, 200 m.
Range: Japan - Ogasawara-shoto (Takeda & Kurata, 1976b); 200 m.

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