CONTENTS OF No. 267, N.S., October, 1923. 

 MEMOIRS : PAGE 



V On the Development of the Hypobranchial, Branchial, and Laryngeal 

 Muscles of Ceratodus. With a Note on the Development of the 

 Quadrate and Epihyal. By F. H. Edgeworth, M.D. (With 

 39 Text-figures) 325 



On Golgi's Internal Apparatus in spontaneously absorbing Tumour 

 Cells. Bv C. Da Fano, Reader in Histology, King's College, Uni- 

 versity of London. (With Plates 19 and 20) ... . 369 



The Golgi Bodies of a Coccidian. By Shana D. King and J. Bronte 

 Gatenby. School of Zoology, Dublin University. (With Plate 21) . 381 



Some Observations upon Spirostomum ambiguum (Ehrenberg). 

 By Ann Bishop, M.Sc, Victoria University, Manchester. (With 

 Plates 22 and 23 and 9 Text-figures) 391 



'' On some remarkable new Forms of Caryophyllaeidae from the Anglo - 

 Egyptian Sudan, and a Revision of the Families of the Cestodaria. 

 By W. F. N. Woodland, Wellcome Bureau of Scientific Research, 

 London. (With Plates 24 and 25 and 1 Text-figure) . . . 435 



Studies in Dedifferentiation. IV. Resorption and Differential Inhibi- 

 tion in Obelia and Campanularia. By J. S. Huxley, M.A., and 

 G. R. DE Beer, B.A., B.Sc. (With Plate 26 and 7 Text-figures) . 473 



CONTENTS OF No. 268, N.S., December, 1923. 



MEMOIRS: 



The Cleavage of the Egg of Lepidosiren paradoxa. By Agnes 

 E. Miller, M.A., Department of Zoology, U^niversity of Glasgow. 

 (With 12 Text-figures) 497 



The Morphology of the Nudibranchiate Mollusc Melibe (syn. 

 Chioraera Leonina Gould). By H. P. Kjerschow Agers- 

 BORG, B.S., M.S., M.A., Ph.D., Williams College, Williamstown, 

 Massachusetts. (With Plates 27 to 37) 507 



Observations upon the Behaviour and Structure of Hydra. By Sheina 

 Marshall, B.Sc, Assistant Naturalist, Scottish Marine Biological 

 Station, Millport. (With 4 Text-figures) 593 



Head Length Dimorphism of Mammalian Spermatozoa. By A. S. 

 Parkes, B.A. (Cantab.), Department of Zoology, University of 

 Manchester. (With 3 Text-figures) ...... 617 



On Brinkmann's System of the Nemertea Enopla and Siboganemertes 

 weberi, n.g. n.sp. By Dr. Gerarda Stiasny-Wijnhoff, Leiden, 

 (With 26 Text-figures) 627 



