Fishes of the Western North Atlantic 451 



2b. Upper teeth with only i cusp. 



4a. Snout in front of mouth considerably longer than from center of mouth to 

 origin of pectorals j dermal denticles pitchfork-shaped, on tall slender pedi- 

 cels. Deania* Jordan and Snyder, 1902." 



Eastern Atlantic, South Africa, Japan, 

 Philippines, Australia, New Zealand. 

 4b. Snout in front of mouth considerably shorter than from center of mouth to 

 origin of pectorals j dermal denticles at most only moderately dentate, on 

 short broad pedicels, or sessile. 

 5a. Teeth similar in the 2 jaws. 



6a. Anterior margin of nostril without long barbel. 



Squalus Linnaeus, 1758, p. 452. 



6b. Anterior margin of nostril with a barbel reaching past corner of 



mouth. Cirrhigaleus Ta-ndk-di^ 19 12.' 



Japan. 



5b. Teeth noticeably dissimilar in the 2 jaws. 



7a. Inner corner of pectoral broadly rounded. 



8a. Blades of dermal denticles on trunk behind ist dorsal smooth, 

 with rounded margins} ridged or striate denticles confined to 

 more anterior part of body. 



Centroscymnus Bocage and Brito Capello, 1 864, p. 493. 

 8b. Blades of dermal denticles with 3 to several ridges 5 with mar- 

 ginal teeth on posterior as well as on anterior parts of trunk. 



Scymnodon Bocage and Brito Capello, 1864.' 



Eastern Atlantic, Straits of Magellan, Japan, New Zea- 

 land, Philippines, India. 



7b. Inner corner of pectoral angular and more or less produced. 



Centrofhorus Miiller and Henle, 1837.' 



Eastern Atlantic, Mediterranean, South Africa, 

 Japan, New Zealand, Australia. 



4. We agree with Fowler (Bull. U.S. nat. Mus., loo [z^], 1941 : 237) that this name should take precedence over 

 A canth'idium as used by Garman (Mem. Harv. Mus. comp. Zool., jiS, 1913 : 215), which is properly a synonym of 

 Etmofterns (see also footnote i, p. 487). 



5. Including Deaniofs Whitley, 1932. 6. Including P/taenofogon Herre, 1935. 



7. Garman (Mem. Harv. Mus. comp. Zool., 36, 1913: 206) has proposed a separate genus, Centroselachus, for spe- 

 cies in which the denticles have numerous ridges, as contrasted with those in which they have only three. But this 

 does not seem to us a sufficiently important difference to be regarded as generic. 



8. Including Lefidorhinus Bonaparte, 1838, and Entoxychirus Gill, 1862. Fowler (Bull. U.S. nat. Mus., 100 [z^], 

 1941 : 223) redivides this group of species between Centrofhorus and En'z.xych'irus. But the differences on which 

 this division is based, i.e., the relative degrees to which the mner corners of the pectorals are produced and the 

 shapes of the dermal denticles, do not seem to us sufficient for generic separation. We may note also that three of the 

 species included by him in Centrofhorus {rossi Alcock, 1898; waitei Thompson, 1930; and foliaceus Giinther, 

 1877) appear to us to belong to Scymnodon. The genus Lefidorhinus of Bonaparte (Nuov. Ann. Sci. nat. 

 Bologna, 2, 1838: 207) has also been revived by Garman (Mem. Harv. Mus. comp. Zool., j<5, 1913: 211). But 

 its type species, the European Squalui squamoius of Bonnaterre (Tabl. Encyc. Meth. Ichthyol., 1788: 12), falls in 

 Centrofhorus as defined here, the inner corners of its pectorals t>eing angular and at least slightly produced. 



