UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 6, No. 15, pp. 353-468, plates 33-48 June 17, 1911 



THE GENUS GYROCOTYLE, AND ITS 



SIGNIFICANCE FOR PROBLEMS 



OF CESTODE STRUCTURE 



AND PHYLOGENY* 



BY 



EDNA EARL WATSON 



CONTENTS. 



PAGE 



A. Introduction 354 



B. History of the Gsgus 356 



C. Gyrocotyle of the Coast of California 363 



I. Occurrence and Host 363 



II. Gross Anatomy 366 



III. Behavior of Living Animal 371 



IV. Characteristics for Separation of Species 376 



V. Key to Species of Gyrocotyle 382 



D. Morphology and Histology of Gyrocotyle 383 



I. Material and Methods 383 



II. Body-covering and Spines 384 



III. Musculature 389 



IV. Reproductive Organs 395 



V. Formation of Compound Egg and Cleavage 406 



VI. Excretory System 407 



VII. Nervous system 409 



VIII. Sense Organs 417 



E. General Discussion 418 



I. Cutieula 419 



II. Orientation 421 



F. Summary 431 



* A dissertation presented to the Faculty of the College of Natural 

 Sciences, in the University of California, in partial satisfaction of the 

 requirements for the degree of Doctor of Philosophy. April, 1910. 



