CONTENTS 



Introduction 335 



External Characters of Chlamydosdachus 336 



General Form of the Body 336 



Position of the Mouth , 338 



Gill-Covers and Spiracles 339 



Fins, Paired and Unpaired 340 



Abdominal or Tropeic Folds 342 



Scales and Teeth 342 



The Endoskeleton 350 



Skull of Chlamydoselachus 350 



The Cranium 351 



The Visceral Skeleton 356 



NoTOCHORD and Vertebral Column 364 



Appendicular Skeleton 370 



Pectoral Fins and Girdle 370 



Pelvic Fins and Pelvis 373 



The Dorsal Fin 377 



The Anal Fin 380 



The Caudal Fin 380 



The Muscular System 381 



The Metameric Muscles 381 



The Axial Muscles 382 



The Appendicular Muscles 394 



The Branchiomeric Muscles 396 



Digestive System and Associated Organs 401 



The Digestive Tube 401 



The Pharynx 402 



Esophagus and Cardiac Stomach 402 



The Pyloric Vestibule 404 



The Pylorus 405 



The Bursa Entl\na 406 



The Valvular Intestine 408 



Rectum and Rectal Gland 410 



The Digestive Tube as a Whole 411 



The Liver 412 



The Pancreas 413 



Organs Associated with the Digestive Tract 415 



The Thyroid Gland 415 



The Spleen 418 



The Respiratory Organs 419 



The Gills 420 



The Spiracles 423 



The Urogenital System 431 



Urogenital System of the Female 431 



Urogenital Sinus in the Female 431 



Organs of Excretion in the Female 434 



Genital Organs of the Female ■ 444 



Urogenital System of the Male 450 



Excretory and Internal Genital Organs 450 



Myxopterygia or Claspers 451 



The Abdominal Pores 453 



33J 



