J. G. KERR. ON THE ANATOMY OF NAUTILUS POMPILIUS. 181 



On some points in the Anatomy of Nautilus 

 pompilius. 



By 

 J. Graham Kerr, Christ's College, Cambridge. 



(PLATES IX. AND X.) 



I. Introduction, p. 181. 



II. The Body-cavity of Nautilus, p. 182. 



III. The Male Genital Ducts and Penis, p. 191. 



IV. The Buccal Nervous System, p. 194. 



V. The Innervation of the "Inner Inferior Lobe," p. 197. 



VI. The Post-anal PapiUse and Nerves, p. 198. 



VII. The Spermatophore-receiving Apparatus, p. 199. 



VIII. The Morphology of the " Arms " of Cephalopods, p. 201. 



IX. The Phylogenetic Belationships of the Cephalopoda, p. 208. 



X. Smimiary of Conclusions, p. 210. 

 Explanation of the Plates, p. 211. 



I. Introduction. 



During the year 1893 Mr Adam Sedgwick very generously 

 placed at my disposal a number of specimens of Nautilus 

 pompilius with the suggestion that I should make an examina- 

 tion of their structure. The specimens were twenty-five in 

 number, of which, however, the great majority were very young 

 and immature. Owing to the method of preservation and to 

 several months' sojourn in sawdust moistened with spirit, the 

 condition of the specimens was usually such as to render them 

 unfit for histological study. Fortunately one of them was 

 sufficiently good to allow the use of the section-method to 

 confirm the results of minute dissection. In the following 

 somewhat fragmentary paper it is my purpose to touch upon 

 what seem to me the more important points at which I have 

 arrived, hoping at some future date, if able to obtain properly 



