SHARKS. 



101 



resembles that of the Dipnoids. In fact this Suborder connects [Case 30.] 

 th'e Ganoids with the Plagiostomes. It contains one family only, 

 represented in the living fauna by two genera Chimera and 

 Callorhynchus. Of the former three species are known Ch. mon- 

 strosa. from deep water off the coasts of Europe, Japan, and the 



Fig. 90. 



Egg of a Dog-fish (Scyttium). (From Magelhan Straits.) 



Cape of Good Hope ; Ch. colliei, off the west coast of North 

 America; and Ch. affinis, off the coast of Portugal. Callorhynchus 

 anlarciicus is common in the southern temperate zone, and differs 

 from the preceding by the curious shape of the snout, which bears 

 a cartilaginous prominence terminating in a cutaneous flap. 



PLAGIOSTOMATA, or Sharks and Rays. 



These have from five to seven gill-openings and the teeth are 

 numerous. They differ greatly among each other with regard to 



