Contents xv 



CHAPTER XXIX. 



THE CLASS ELASMOBRANCHII, OR SHARK-LIKE FISHES. 



The Sharks. — Characters of Elasmobranchs. — Classification of Elasmobranchs. 

 — Subclasses of Elasmobranchs. — The Selachii. — Hassc's Classification of 

 Elasmobranchs. — Other Classifications of Elasmobranchs. — Primitive 

 Sharks. — Order Pleuropterygii. — Order Acanthodii. — Dean on Acanthodii. 

 — Order Ichthyotomi 506 



CHAPTER XXX. 



THE TRUE SHARKS. 



Order Notidani. — Family Hexanchida;. — Family Chlamydoselachida;. — Order 

 Asterospondyli. — Suborder Cestraciontes. — Family Heterodontidae. — Edes- 

 tus and its Allies. — Onchus. — Family Cochliodontida;. — Suborder Galei. — 

 Family Scyliorhinida;. — The Lamnoid, or Mackerel-sharks. — Family Mit- 

 sukurinidae, the Gobhn-sharks. — Family Alopiidte, or Thresher-sharks. — 

 Family Pseudotriakidce. — Family Lamnidoe. — Man-eating Sharks. — Family 

 Cetorhinidae, or Basking Sharks. — Family Rhineodontid^e. — The Carcharioid 

 Sharks, or Requins. — Family Sphyrnidae, or Hammer-head Sharks. — The 

 Order of Tectospondyli. — Suborder Cyclospondyli. — Family Squalidae. — 

 Family Dalatiidae. — Family Echinorhinidas. — Suborder Rhinae. — Family 

 Pristiophoridae, or Saw-sharks. — Suborder Batoidei, or Rays. — Pristidida;, 

 or Sawfishes. — Rhinobatida?, or Guitar-fishes. — Rajidae, or Skates. — Narco- 

 batidce, or Torpedoes. — Petalodontida;. — Dasyatidce, or Sting-rays. — 

 Myliobatidae. — Family Psammodontids. — Family Mobulidae 523 



CHAPTER XXXI. 



THE HOLOCEPHALI, OR CHIMERAS. 



The Chimaeras. — Relationship of Chimeras.— Family Chimajridte.— Rhino- 

 chimaerida;.— E.xtinct Chima-roids.^Ichthyodorulites 561 



CHAPTER XXXII. 



THE CLASS OSTRACOPHORI. 



Ostracophores.— Nature of Ostracophores.— Orders of Ostracophores.— Order 

 Heterostraci.— Order Osteostraci.— Order Antiarcha.— Order Anaspida. ... 568 



CHAPTER XXXIII. 



,'\RTHRODIRr:S. 



The Arthrodires.— Occurrence of Arthrodires.— .Arthrognathi.— Anarthrodira.— 

 Stegothalami.—Arthrodira.—Temnothoraci.—Arthrothoraci.— Relations of 



