Sakai, 1963
Near genus Merocryptus A. Milne Edwards (1873), but the dorsal surface is obviously depressed. The broad front is markedly produced forward and upward; the low gastric region is very narrow; the small cardiac region is slightly convex whereas the intestinal region is markedly convex and its posterior boundary is upturned. The hepatic region is moderately prominent and its dorsal surface is depressed to form a semicircular facet surrounded by a series of elongated tubercles. Below this facet a small hepatic lobe is visible in dorsal aspect. The outer margin of the branchial region has two projections; the anterior one is a small facet just posterior to that on the hepatic region, directed obliquely downward. The posterior one forms the prominent lateral wing-like lobe, upturned at the apex whence a transverse row or crest of pearly tubercles extends inward to end in an irregular facet, also more or less surrounded by elongated tubercles. The male abdomen is broadly triangular in outline, not so markedly elongate as in Merocryptus. The anterior male pleopod is slender, sinuous, strongly curved inward near the apex and beset with scattered setae. (Sakai, 1963)
Genus endemic to Japan (Komatsu & Takeda, 2001).
Type species: Merocryptoides frontalis Sakai, 1963.
Species included:
Merocryptoides frontalis Sakai, 1963
Merocryptoides ohtsukai Komatsu & Takeda, 2001
Merocryptoides peteri Komatsu & Takeda, 2001