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XIX. — On the Cranial Nerves of Chimsera monstrosa (Linn. 1754) ; with a Discussion 

 of the Lateral Line System, and of the Morphology of the Chorda tympani. 

 By Frank J. Cole, Demonstrator and Assistant Lecturer of Zoology, University 

 College, Liverpool. Communicated by Professor Ewart, M.D., F.R.S. (With 

 Two Plates.) 



(Read June 15, 1896.) 

 CONTENTS. 



A. Introductory, 



B. Historical, .... 



C. Classification of Sensory Canals, 



(1) General Scheme, 



(2) The Sensory Canals one organ, 



(3) Difficulties to above, 



(4) Garman's Classification, 



D. Sensory Canals of Chimsera, 



E. The Eye Muscle Nerves, . 



(1) Oculo-motor, 



(2) Patheticus, . 



(3) Abducens, . 



F. Trigeminus, 



(1) Eoots of Vth and Buccal, 



(2) Literature, . 



G. The Vllth or " Facial Proper," 



PAGE 



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632 



635 

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640 



642 

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 643 

 644 



644 

 644 

 647 



651 



H. Lateral Line System, . . . 653 



(1) Lateralis, .... 656 



(2) Auditory, . . . .656 



(3) Literature of Facial and Lateral 



Line System, . . . 656 



(3a) Homology of Chorda tympani, . 657 



(3b) Typical hyomandibular, . . 662 



(3c) Boots of Vth and Vllth, . . 662 



J. Glossopharyngeal, . . . .664 



(1) The Gills of Chimsera, . . 664 



(2) Literature, . . . .666 

 K. Vagus, . . . . .666 



(1) Vagus of Chirnezra very primitive, . 666 



(2) Literature, . . . .670 

 L. Anterior Spinal Nerves, . . . 672 

 Postscript, . . . . .673 

 Summary, ..... 674 

 Bibliography, . . . . .676 



A. Introductory. 



This investigation first commenced in the examination of a few special points which 

 had arisen in connection with Professor Ew art's investigations on the Cranial Nerves and 

 Lateral Sense Organs of Elasmobranchs. As this examination revealed facts of more 

 interest than was expected, it occurred to me to investigate very thoroughly the whole 

 of the cranial nerves of this animal, and to publish the results as a continuation of the 

 work already alluded to. The research turned out to be much easier and more interesting 

 than I had anticipated, and, as regards its cranial nerves at any rate, Chimsera is un- 

 rivalled among vertebrates, first, for the ease with which its nerves may be dissected, 

 and second, for the almost ideal results that are to be obtained. The endless perplexity 

 and mystification produced by the study of the trigeminal and facial nerves of the 

 cartilaginous fishes, — dispelled to a very great extent, it is true, by the researches of 



VOL. XXXVIII. PART III. (NO. 19). 4 T 



