2 34 Memoir Sears Foundation for Marine Research 



of carnivorous mammals (weasels, etc.) for many years previous. To avoid the confusion 

 that would result from the use of this family name for sharks, as well as for mammals, it 

 seems wiser to replace it with "Triakidae" White,^" first used by that author in a more 

 restricted sense, but subsequently expanded by her.^" 



Key to Genera 

 la. Nostril connected with mouth by a groove. Scylliogaleus Boulenger, 1902. 



Natal, southeastern Africa. 



lb. Nostril entirely separate from mouth. 



2a. Teeth low, rounded, or with only slightly sinuous cutting edge. 



Mustelus Link, 1790, p. 240. 

 2b. Teeth somewhat compressed, with 3 to 5 pointed cusps. 



3a. No labial furrow at corner of mouth. Eridacnis H. M. Smith, 191 3. 



Philippines. 



3b. A labial furrow at corner of mouth. 



4a. Anterior margin of nostril expanded as a well developed and conspicuous 

 barbel. Fwr Whitley, 1943. 



Australia.'' 



4b. Anterior margin of nostril not expanded as a well developed barbel. 

 5a. Spiracle moderately large, easily seen. 



Triakis Miiller and Henle, 1838, p. 235.' 

 5b. Spiracle minute or absent. 



6a. Caudal peduncle with precaudal pit above; lower anterior cor- 

 ner of caudal expanded as a lobe. 



Triaenodon Miiller and Henle, 1837. 



Tropical Indian Ocean, Red and Arabian Seai; 

 India and Ceylon, Malaysia, Melanesia and 

 Polynesia, Hawaiian Islands, Cocos Island, and 

 Panama. 

 6b. Caudal peduncle without precaudal pit; lower anterior corner 

 of caudal not expanded as a lobe. 



Leptocharias Miiller and Henle, 1838. 

 West Africa. 



Remarks. The separation between the only two triakid genera that are known to occur 

 in the Atlantic, Triakis and Mustelus, is partly bridged by T. macidata of the west coast 

 of South America, the teeth of which are only a little more definitely cuspidate than those 

 of Mustelus dorsalis of the same geographic province." 



3a. Amer. Mus. Novit., 879, 1936: 19. 3b. Bull. Anier. Mus. nat. Hist., 74, 1937: 121. 



4. Whitley, Aust. Zool., 10 (2), 1943: 167; Rec. Aust. Mus., 7 (4), 1943: 397 > Aust. ZooL, to, 194+: 260, pi. 3. 



5. Including R/iinotriacis Gill, 1862, Calliscylliutn Tanaka, 1912, and Hemhriakis Herre, 1923, all of which seem 

 clearly referable to the old genus Triakis (see p. 235). 



6. For discussion, see Bigelow and Schroeder (Proc. Boston Soc. nat. Hist., 41 [8], 1940: 430- 



