34 BULLETIlSr 10 0, UNITED STATES NATIONAL MUSEUM 



Genus SCYLIORHINUS Blainville 



Scyliorhinus Blainville, Bull. Soc. Philom. Paris, 1816, p. 121. (Type, 



Squalus canicula Linnaeus, designated by Gill, Ann. Lyceum Nat. Hist. 



New York, vol. 7, p. 407, 1862.) 

 Scylliorhmus Blainville, Faune Frangaise, Poissons, p. 68, 1825. (Type, 



Sgtialus catnlus Linnaeus.) 

 Catulus (not Kniphof, 1759, in Insects) Valmont, Diet. Hist. Nat. Paris, vol. 



10, p. 114, 17G9; vol. 12, p. 421, 1769. [Type, Catulus vulgaris Valmont= 



Squalus cmvicula Linnaeus, monotypic (inadmissible).] — Andrew Smith, 



Proc. Zool. Soc. London, 1837, p. 85. (Type, Squalus canicitla Linnaeus, 



designated by Fowler, Proc. Acad. Nat. Sci. Philadelphia, 1908, p. 53.) 

 Scyllium Cuviee, Regne animal, vol. 2, p. 124, 1817. (Type, Squalus canicula 



Linnaeus, designated by Jordan and Evermann, Genera of fishes, pt. 1, p. 



97, 1917.) 

 Scylliodus Agassiz, Poissons fossiles, vol. 3, p. 377, 1843. (Type, ScylUodus 



antiqmis Agassiz, monotypic.) 

 Thyellina Agassiz, idem, p. 378. (Type, ThyeUina angusta Agassiz, monotypic.) 



(Fossil.) 

 Palaeoscyllium Wagnee, Anz. Bayer. Akad., vol. 44, p. 291, 1857. — Marek, 



Palaeontographica, Beitr. Naturg. Vorwelt, vol. 11, p. 67, 1863. (Type, 



Palaeoscyllium decheni Marek, monotypic.) (Fossil.) 

 Trigonodus Winklee, Arch. Mus. Teyler, vol. 4, p. 20, 1876. (Type, Trigonodus 



primus Winkler.) (Fossil.) 



Body shorter than tail. Head short. Snout obtuse, short. Mouth 

 large, labial folds on lower jaw. Teeth in numerous rows, each tooth 

 with median larger cusp and one to several small lateral cusps. Nos- 

 trils distinct from mouth, when posterior nasal valve cirroid with 

 rudimentary nasoral groove; nasal valves confluent, hind edge free 

 and entire. Gill openings small, last above pectoral. Spiracle small, 

 close after eye. Dorsals and anal small, latter largest fin. First 

 dorsal above or behind ventral bases. Tail entire, caudal moderate or 

 short. Ventrals of male more or less concrescent above claspers. 



Small sharks of warm seas. Fossils known from the Cretaceous 

 and Tertiary. In comparison with Galeus, Smith says: "The genus 

 is indeed without serrations at the upper edge of the caudal fin, 

 though these may sometimes be traced in the difference between the 

 large spring scales in the upper rows on each side and the smaller and 

 smoother ones in the median dorsal line at the said spot ; but it has a 

 compensation for them in the stronger development of the spiny scales 

 on each side of the body above and behind the anal fin, which almost 

 exactly resemble jaw teeth. These scales literally form a rasp, which 

 the fish uses as a defensive weapon." 



The Qgg cases are oblong and with long filamentous tendrils at each 

 corner. As expelled, two at a time, the first pair of the filaments of 

 the egg cases are wound around a branch of seaweed or other object 

 by the female and there the egg capsule is left to its fate. The young 

 sharks are said to hatch in six months' time. 



