Fishes of the Western North Atlantic 293 



small lobe; teeth alike in the 2 jaws, erect, narrow-cusped in front, but broad and strongly 

 oblique along sides of jaws, their outer margins deeply notched, their edges smooth or 

 slightly wavy at base, their bases not swollen. Characters otherwise those of the family. 



Remarks. These are small, warm-water sharks, seldom if ever encountered far from 

 land. In some localities they are the most abundant sharks. All are fish-eaters, so far as 

 known, and are entirely harmless. 



Range. Oaastal waters in tropical and warm-temperate seas; Morocco to Cameroon; 

 North Carolina (accidentally to Bay of Fundy) to Uruguay in the Atlantic; Mexico to 

 Panama in the eastern Pacific; China and Japan to Australia in the western Pacific; Indian 

 Ocean (including Red Sea and Arabian Gulf) south to Natal. 



Fossil Teeth. Eocene to Miocene, Europe. 



Species. Of the dozen or so named forms that fall in Scoliodon, as defined here, 

 all but one (possibly two) are Indo-Pacific and represent not more than eight good species 

 at most. And it is likely that critical comparison of collections from different seas would 

 result in a further reduction, because terrae-novae of the Atlantic, the only species of which 

 a large series has been examined, shows considerable variation (see discussion, p. 299); 

 hence, others may also. Furthermore, the differences that now seem to be diagnostic are 

 so inconspicuous, and the several supposed species all resemble one another so closely in 

 general appearance, that identification of individual specimens calls for close examination 

 if they happen to be from regions where more than one kind is to be expected. For this 

 reason it is not yet possible to define the ranges of any of the Indo-Pacific species in detail. 



Tentative Key to Species* 



I a. Origin of 2nd dorsal posterior to base of anal; labial furrow confined to comer of 

 mouth, not extending inward along either jaw. dumerilii Bleeker, 1 8 56. 



East Indies, southern China. 



lb. Origin of 2nd dorsal over rear part of base of anal ; labial furrow extends inward from 

 comer of mouth for some distance along one jaw or both. 



2a. Lower labial furrow considerably longer than upper, which is very short; base of 

 anal about twice as long as base of 2nd dorsal. sorrakowah Cuvier, 1 829. 



India, Malaysian region, China, 

 Japan. 

 2b. Upper labial furrow at least as long as lower, if latter is present; base of anal less 

 than twice as long as base of 2nd dorsal. 

 3a. Origin of 2nd dorsal definitely anterior to rear end of base of anal. 



4a. A short labial furrow on upper jaw directed outward at right angles to 

 the jaw; none on lower jaw. jordani Ogilby, 1908. 



Australia. 



2. Carcharias falasorrah of Cuvier (Regne Anim., 2, 1829: 388), commonly referred to Scoliodon, falls in 

 Hyfofrion 3» here defined, its teeth being conspicuously serrate or denticulate at the base on the outer side. 



