Fishes of the Western North Atlantic 109 



Odontasfis americanus Ihering, Rev. Mus. paul., 2, 1 897: 35 (listed, Rio Grande do Sul, Brazil) ; Thompson, 

 Mar. biol. Rep. Cape Town, 2, 1914: 146 (S. Africa, not seen) ; Lahille, Physis. B. Aires, 5, 1921: 63; 

 also Enum. Feces Cartilag. Argent., 1 921: 15 (Argentina); Devincenzi, An. Mus. Montevideo, (2) 2, 

 1926: 202 (size, weight, no descr., Uruguay). 



Family SCAPANORHYNCHIDAE 

 Goblin Sharks 



Characters. Two dorsal fins, the ist very much shorter than caudal, the rear end of 

 its base anterior to origin of pelvicsj caudal slightly more or less than Vs of total length, 

 its axis raised only very slightly, its lower anterior corner not expanded as a distinct lobe; 

 caudal peduncle not greatly depressed or expanded laterally; sides of trunk without longi- 

 tudinal dermal ridges; jaws greatly protrusible (much more so than in any other sharks) 

 and widely expansible; snout greatly elongate; 5th gill opening over or anterior to origin 

 of pectoral ; gill arches without rakers and not interconnected by a sieve of modified den- 

 ticles; nostrils entirely separate from mouth, their anterior margins without barbels; 

 spiracles present; lower eyelid without nictitating membrane or subocular fold; teeth simi- 

 lar in the two jaws, with thorn-like cusps, smooth-edged, with or without lateral denticles, 

 on broad bases; skull of normal shape {i.e.y not widely expanded laterally) ; rostral carti- 

 lages 3, united anteriorly as a long rod; radials of pectoral mostly borne on mesopterygium 

 and on metapterygium ; meso- and metapterygia not separated by a foramen ; heart valves 

 in 3 rows. Development not known, but probably ovoviviparous. 



Genera. Only one genus, Scapanorhynchus Woodward, 1889, is known. 



Range. Modern representatives of Scapanorhynchus^ are known from Japan, the 

 coast of Portugal, and perhaps from Australia/ 



Fossil remains of the genus, mostly from the Cretaceous, have been found at many 

 localities in Europe, North and South America, Asia, Africa and New Zealand. 



Family ISURIDAE 



Mackerel Sharks, Man-eater Sharks 



Characters. Two dorsal fins, the ist much shorter at base than length of caudal, the 

 rear end of its base far in advance of origin of pelvics; 2nd dorsal and anal much smaller 

 than ist dorsal; caudal less than Vs of total length, lunate in form, its axis steeply raised; 

 caudal peduncle strongly depressed dorso-ventrally and widely expanded laterally, form- 

 ing a prominent keel on each side, extending well out on the caudal, with a less definite 

 longitudinal keel close below it on the anterior part of caudal in some species; sides of 

 trunk, anterior to anal, without longitudinal dermal ridges; upper and lower precaudal 

 pits well developed; inner margins of pelvics entirely separate, posterior to cloaca; snout 

 not very elongate and jaws not greatly protrusible; 5th gill opening in front of origin of 



1. How many species these represent still remains unsettled. 



2. According to Whitley (Fish. Aust, /, 1940: 136), the report of this Shark from Murray River (Zietz, Trans, 

 roy. Soc. S. Aust., 52, 1908 : 291) is open to doubt. 



