CONTENTS OF No. 216.-New Series. 
MEMOIRS 
PAGE 
On Certain Features in the Development of the Alimentary Canal in 
Lepidosiren and Protopterus. By J. Graham Kerr, Pro- 
fessor in the University of Glasgow. (With 13 Text-figures) 483 
The Phylogeny of the Tracheae in Araneae. By W. F. Purcell, 
Ph.D., Bergvliet, Diep River, near Cape Town. (With Plate 28, 
and 21 Text-figures) ..... 519 
On the Reproduction of Kalpidorhynchus arenicolae (Cnghm.). 
By Margaret Robinson, University College, London. (With 
Plate 29) . . . . . . .565 
Studies in the Experimental Analysis of Sex. By Geoffrey Smith. 
(With Plate 30) ...... 577 
Some Points in the Physiology of Lamellibranch Blood-Corpuscles. 
By G. H. Drew, B. A. Cantab. (With Plate 31) . . 605 
Note on the Cytology of Calothrix fuse a. By Dr. N. H. Swel- 
LENGREBEL, Amsterdam. (With Plate 32) . . 623 
Tropidonotus and the “ Archenteric Knot ” of Ornithorhynchus. By 
Richard Assheton, M. A. (AVith Plate 33) . . 631 
Title, Index, and Contents. 
