Memoir Sears Foundation for Marine Research 



Key to Species 



I a. Origin of anal opposite rear base of dorsal, 

 lb. Origin of anal under middle of base of dorsal. 



perlo Bonnaterre, p. 88. 

 dakini Whitley, 1931. 



Australia.' 



He-ptranchias ferlo (Bonnaterre), 1788 



Seven-gilled Shark 



Figures 10, 11 



Study Material. Female, 932 mm. long, containing 9 embryos, and also an adult male 

 of 698 mm., both from Havana, Cuba (Harv. Mus. Comp. Zool., No. 36897) ; specimen 

 of 732 mm., from Nice, France (Harv. Mus. Comp. Zool., No. 945)} also specimens of 

 957, 980 and 255 mm. from Japan, the latter newborn with umbilical scar still faintly 

 visible (Harv. Mus. Comp. Zool., No. 35070, 1040, 1299). 



Distinctive Characters. The presence of 7 gill slits combined with narrow head and 

 pointed snout separates ferlo from all other Atlantic sharks. 



Figure 10. Heftranchias ferlo, male, about 689 mm. long, from the north coast of Cuba (Harv. Mus. Comp. 

 Zool., No. 35897) ; A Anterior part of head, about Y2 natural size. B Right-hand nostril, about 1.3 x. C Der- 

 mal den,ticles, about 37 x. Z) Lateral view of dermal denticle, about 64 x. E Apical view of dermal denticle, 

 about 64 X. 



3. An additional diagnostic character, according to Whitley (Aust. Zool., 6, 1931: 310), is anal base as long as 

 dorsal base in ferlo, but shorter than the latter in dakini. Actually, however, no distinction can be drawn in this 

 respect, the anal being appreciably shorter than the dorsal in two of the three Atlantic specimens of ferlo that we 

 have seen. 



