The Embryology of Heterodontus japonicus 



669 



Whitley's excellent representation (1940, Fig. 52) of a female Heterodontus phillipi, 

 said to be after Waite, bears a remarkable resemblance to Saville-Kent's photograph 

 reproduced as my Text-figure 4. The four posterior gill-slits and the color pattern of the 

 sides of the body are more distinct in Whitley's figure. In addition, Whitley (1940, Fig. 

 53) has published an excellent original drawing of a female Heterodontus phillipi. Concern- 

 ing the coloration, he writes: "Color grayish to light brownish. A dark blotch on snout. 

 A blackish interorbital bar as broad as eye, continued and expanded below eye. A series 

 of blackish stripes on body rather like harness." 



Glands associated with the dorsal fin spines of certain sharks have been studied by 

 Evans (1924). In Squalus, this author found a large groove along the base of each dorsal 

 spine, on the side facing the fin. The groove is filled with a follicular gland, which was 

 studied microscopically. Evans cites evidence that the secretion discharged by this gland 

 has venomous properties. He states further that the dorsal fin spines of Cestracion 

 (Heterodontus) phillipi are similar to those of Squalus, but with a shallower groove. This 

 groove likewise contains a follicular gland, but the nature of the secretion was not studied 

 in Heterodontus. The author makes comparisons of the dorsal fin spines of Squalus and 

 Cestracion (Heterodontus) with those of some fossil Cestracionts, and of Hyhodus. The 

 presence of a large groove along the bases of the dorsal fin spines of these fossil forms 

 suggests that, in life, glands were present at the bases of these spines also. 



\ 



Text-figure 9. 



Dorsal view of the very young female Port Jackson Shark, Heterodontus phillipi, about 225 mm. (8.8 inches) 



long, shown in lateral view in Text-figure 8. The drawing was made while the specimen was fresh. 



After Maclay and Macleay, 1879, Fig. 1, pi. 22. 



