CONTENTS. 



J 



CONTENTS OF No. 217, N.S., APRIL, 1910. 



MEMOIRS : PAGE 



On the Anatomy and Systematic Position of Incisiira (Scissu- 

 rella) Lytteltonensis. By Gilbert C. Bourne, Fello^r of 

 Merton College, Oxford, and Linacre Professor of Comparative 

 Anatomy. (With Plates l-o) . . . .1 



The Eye of Pecten. By W. J. Dakin, M.Sc, Demonstrator and 

 Assistant Lecturer in Zoology, University of Belfast. (With 

 Plates 6 and 7, and 2 Text-figures) . . .49 



Observations on Certain Blood-Parasites of Fishes occurring at 

 Eovigno. By Prof. E. A. Minchin, M.A., and H. M. Woodcock, 

 D.Sc. (With Plates 8-10) . . .113 



On Ganymedes anaspidis (nov. gen., nov. sp.) : a Gregarine 

 from the digestive tract of Anaspides tasmanise (Thomp- 

 son). By Julian S. Huxley. (With Plate 11, and 5 Text- 

 figures) . . . ■ • .155 



The Foetal Membranes of the Vertebrates. By A. A. W. Hdbrecht 177 



CONTENTS OF No. 218, N.S., JUNE, 1910. 



MEMOIRS : 



The Structure and Life-History of Crithidia melophagia 

 (Flu), an Endo-parasite of the Sheep-Ked, Melophagus 

 ovinus. By Annie Porter, B.Sc.Lond., Zoological Research 

 Laboratory, University College, London. (With Plates 12 and 

 13, and 15 Text-figures) . . .189 



Studies in the Experimental Analysis of Sex. By Geoffrey 

 Smith, Fellow of New College, Oxford. (With Plate 14) . 225 



Some Observations on a Flagellate of the Genus Cercomonas. By 



_^ C. M. Wenyon, M.B., B.S., B.Sc, Protozoologist to the London 



^ School of Tropical Medicine. (With 19 Text-figui-es) . 241 



Some Observations on a New Gregarine (Metamera schubergi 

 nov. gen., nov. spec). By H. Lyndhurst Duke, B.A., B.C. 

 Cantab. (With Plates 15 and 16) . . . . 261 



On the Anatomy of Histriobdella Homari. By Cresswell 

 Shearer, M.A., Trinity College, Cambridge. (With Plates 17- 

 20, and 5 Text-figures) ..... 287 



On the Artificial Culture of Marine Plankton Organisms. By 

 E. J. Allen, D.Sc, Director of Laboratories and Secretary of 

 the Marine Biological Association, and E. W. Nelson, Assistant 

 Naturalist ...... 361 



