CONTENTS OF No. 213.-New Series. 
MEMOIRS : 
PAGE 
Development and Origin of the Eespiratory Organs in Arane®. By 
W. F. Purcell, Ph.D., Bergvliet, Diep Eiver, near Cape Town. 
(With Plates 1—7, and 7 Text-figures) . . . 1 
Notes on the Nephridia of Dinophilus and of the Larv® of Poly- 
gordius, Echiurus, and Phoronis. By E. S. Goodrich, F.E.S., 
Fellow of Merton College, Oxford. (With Plate 8) . .Ill 
Further Notes on a Trypanosome found in the Alimentary Tract of 
Pontohdella muricata. By Muriel Eobertson, M.A., Car- 
negie Eesearch Fellow ; Junior Assistant to the Professor of 
Protozoology in the University of London. (With Plate 9, and 
5 Text-figures) ...... 119 
