The ichthyological collections brought together in various parts of New Guinea by staff members of the Rijksmuseum van Natuurlijke Historie in 1954 and 1955 (cf. Boeseman, 1963), contain a series of scorpion-fishes which are here described as a new species, representing a new genus. Cheroscorpaena genus novum Mainly characterized by the, in the Scorpaenidae unique, pectoral fins, which consist of nine rays connected by a membrane, followed ventrally by three entirely detached simple rays of about the same length as the main fins. The type and hitherto only species of this genus is: Cheroscorpaena tridactyla species nova (pl. 1) D XIII. 7 or 8, A III. 6 or 7, Ρ i. 8-i-i-i, V I. 5, C 8 to 10 (branched rays only), gill-rakers on outer branchial arch 7 or 8 + 1 + 16 to 20, scales very small, 85 to 90 on body longitudinally, pores in lateral line about 28. A for a member of the family Scorpaenidae fairily slender fish, depth 3.1 to 3.3 in standard length; greatest width 1.6 to 1.8 in greatest depth. Anterior profile almost straight from the blunt snout to the first dorsal spine (in the largest specimen slightly curved, concave on the snout, convex on the nape); outline of back moderately convex towards the tail; outline of body ventrally only slightly convex, with the deepest part of the body between the 2nd and 3rd dorsal spines and the basis of the ventral fins. Head fairly large, 2.7 to 2.8 in standard length, with a more or less triangular outline. Snout blunt, anterior part vertical; eye small, its diameter about 7 in head and 2.5 in snout. Nostrils large, the posterior one in front of lower half of eye, the anterior one in advance of the posterior one and