CONTENTS OF No. CXXXI.— New Series. 



MEMOIRS: 



PAGE 



A New Branchiate Oligochaete (BranchiuraSowerbyi). By Frank. 



E. Beddard, M.A., Prosector to the Zoological Society of London, 

 Lecturer on Biology at Guy's Hospital. (With Plate XIX) . . 325 



The Formation of the Germ-layers in Crangon vulgaris. By W. 



F. R. Weldon, M.A., F.R.S., Fellow of St. John's College, Cam- 

 bridge ; Jodrell Professor of Zoology in University College, London. 

 (With Plates XX, XXI, and XXII) . . . .343 



The Pigment Cells of the Retina. By J. S. Boden and F. C. 

 Sprawson, Students of Medicine, King*^ College, London . .365 



Observations upon the Development of the Segmentation Cavity, the 

 Archenteron, the Germinal Layers, and the Amnion in Mammals. 

 By Arthur Robinson, M.D., Senior Demonstrator of Anatomy at 

 the Owens College, Manchester. (With Plates XXIII, XXIV, 

 XXV, XXVI, and XXVII) 369 



