460 GEOGRAPHICAL ZOOLOGY. [part iv. 



Subclass IV.— CHONDROPTERYGIL (Sharks 

 and Rays.) 



Order I.—HOLOCETHALA. (Chimceras.) 



Family 98.— CHIMiERID^E. (2 Genera, 4 Species.) 

 " Shark-like marine fishes, snout of .the male with a prehensile 



organ. 



Distribution. — Northern and Southern temperate seas. Chi- 

 mccra is British. 



Order II.—PLAGIOSTOMATA. 

 Sub-order. — Selachoidea. (Sharks.) 



Family 99.— CARCHARIID^F, (11 Genera, 59 Species.) 



" Sharks with two dorsals and a nictitating membrane." 



Distribution. — Seas of the Arctic, temperate, and tropical 

 regions. Species of Galeus and Mustelus have occurred on our 

 coasts. 



Family 100.— LAMNIDiE. (5 Genera, 7 Species.) 



" Sharks with two dorsals and no nictitating membrane." 



Distribution. — Temperate and tropical seas. Species of 

 Lamna, Alopecias, and Selache have occurred in British seas. 



