Fishes of the Western North Atlantic 99 



Range. Both sides of warm temperate and tropical North Atlantic, including the 

 Mediterranean; eastern South America south to northern Argentina; South Africa; India; 

 Australia; China; Japan. 



Fossil Teeth. Lower Cretaceous to Pliocene, Europe; Upper Cretaceous to Miocene, 

 South America; Upper Cretaceous to Pliocene, North America, New Zealand; Upper Cre- 

 taceous, Asia; Paleocene to Pliocene, Africa; Miocene, Australia, West Indies. 



Species. The members of this genus fall into two easily separable divisions, the one 

 represented by a single well defined species (ferox Risso), the other by a group of named 

 forms, so clearly allied one to another that it is still an open question how many of them 

 deserve separate specific names. While awaiting comparison of specimens from different 

 ocean areas, the accompanying key recognizes differences which may later prove merely 

 varietal. 



Provisional Key to Species 



I a. 1st upper tooth notably smaller than 2nd, each tooth usually with 2 denticles on each 

 side; 3rd upper tooth followed by 4 very much smaller teeth. ferox Risso, 1 8 lO. 



Eastern Atlantic, 

 Mediterranean. 



lb. 1st upper tooth only slightly smaller than 2nd, if so at all; each tooth usually with i 

 denticle only (rarely 2) on each side, or with none; 3rd upper tooth followed by 2 or 

 3 much smaller teeth at most. 



2a. 3rd upper tooth followed by 2 or 3 much smaller teeth, no wide gap between these 

 and the next large (5th or 6th) tooth. flatensis Lahille, 1928. 



Argentina. 



arenarius Ogilby, 1 9 1 1 . 



Australia.'* 



2b. 3rd upper tooth followed by i much smaller tooth only, the latter separated from 

 the succeeding large tooth by a broad gap. 



3a. Snout broadly rounded; inner margin of pectoral only ^/^ as long as outer; 

 no labial furrow at angle of mouth. tricuspidatus Day, 1888. 



India, China." 

 3b. Snout pointed; inner margin of pectoral more than Ys as long as outer; well 

 marked labial furrows at corners of mouth. 



4a. Lateral denticles lacking on most teeth, minute on others; length of 

 longest tooth less than Yi diameter of eye. owstoni Garman, 19 13. 



Japan. 



4b. Most or all of teeth with a well developed lateral denticle on each side; 

 length of longest tooth at least % diameter of eye. 



/i2Mr«j Rafinesque, 1810, p. lOO.'^ 



13. Published descriptions are not suinciently detailed for critical comparison of flatensii with arenarius. 



14. Fang and Wang, Contr. Biol. Lab. Sci. Soc. China, 8, 1932: 241. 



15. It has been suggested recently that the American form {liUoralis) differs from the European taunts in having 

 no denticles on its first and fourth upper teeth (Giltay, Mem. Mus. Hist. nat. Belg., Hors Serie, 5, Fasc. 3, 1933 : 

 7). Our own examination of specimens of various sizes from southern New England and the vicinity of New 

 York shows that while the teeth in question are smooth in some small specimens (about three feet Ions), they have 



