Hemigaleidae
by S. Branstetter
Head of normal shape, not laterally expanded into cephalofoil. Snout depressed, usually pointed or gently rounded; nostrils without barbels; anterior, medial and posterior nasal flaps well developed. Mouth parabolic in shape, labial furrows long; upper teeth large, triangular, broad cusped, with cusplets, lower teeth narrow cusped, no cusplets. Eyes nearly circular to almond-shaped; nictitating membrane present, internal; subocular ridge absent. Spiracle present. Gill-slits 5, all similar in length, fifth and usually fourth over or posterior to pectoral fin origin. Two dorsal fins, midpoint of first equidistant between pectoral and pelvic bases, or slightly closer to pectoral, all of first always anterior to pelvic origin, second dorsal slightly smaller than first; inter-dorsal ridge absent; pectoral fins relatively short, posterior edge concave; pre-caudal pits present above and below; lateral keels on peduncle absent; caudal fin well developed, both lobes well differentiated; sub-terminal notch present. Intestinal valve of corkscrew type, 4-6 turns present. Colour grey to brown above, whitish below.
Demersal to pelagic in continental shelf waters. Viviparous, small number of young. Feeds primarily on fishes, crustaceans, squids.
Genera 4; in Clofnam area 1.
Recent revisions: Compagno (1979) Hemigaleidae intermediate between Triakidae and Carcharhinidae).