IV CONTENTS. 



PAGE 



On tlie Morphology of the Cheilostomata. By Sidney P. Harmer, 

 Sc.D., F.U.S. (With Plates 15— 18) . . . .263 



On the Development of Sagitta ; with Notes on the Anatomy of 

 the Adult. By L. Doncaster. (With Plates 19—21) . 351 



CONTENTS OF No. 183, N.S., DECEMBER, 1902. 



MEMOIRS : 



On a Cestode from Cestracion. By William A. Haswell, M.A., 

 D.Sc., F.R.S. (With Plates 22—24) . . . .399 



The Development of Lepidosiren par ado xa. — Part III. De- 

 velopment of the Skin and its Derivatives. By J. Graham 

 Kerr. (With Plates 25—28) . . . , .417 



The Metamorphosis of Corystes Cassivelaunus (Pennant). 

 By Robert Gurney, B.A.(Oxon.), P.Z.S. fWith Plates 

 29"— 31) 461 



Artificial Parthenogenesis and Fertilisation : a Review. By 

 Thomas H. Bryce ...... 479 



CONTENTS OF No. 184, N.S., FEBRUARY, 1903. 



MEMOIRS: 



The Movements and Reactions of Presh-water Planarians; a Study 

 in Animal Behaviour. By Raymond Pearl, Ph.D., Instructor 

 in Zoology in the University of Michigan, Ann Arbor, Michigan, 

 U.S.A 509 



On the Diplochorda. — Part IV. On the Central Complex of 

 Cephalodiscus dodecalophus, McI. By A. T. Masterman, 

 M.A., D.Sc., Lecturer on Zoology, School of Medicine, Edin- 

 burgh. (With Plates 32 and 33) ... . 715 



On Hypurgon Skeati, a new Genus and Species of Compound 

 Ascidians. By Igerna B. J. Sollas, B.Sc.Lond. (With Plates 

 34 and 35) 729 



The Anatomy of Arenicola assimilis, Ehlers, and of a New 

 Variety of the Species, with some Observations on the Post- 

 larval Stages. By J. H. Asiiwortii, D.Sc. (With Plates 36 

 and 37) 737 



Title, Index, and Contents. 



