CONTENTS OF No. 228-New Series. 
MEMOIRS : 
PAGE 
The Mouth-Parts of Some Beetle Larvae (Dascillidae and Scara- 
baeidse), with especial reference to the Maxillulae and Hypopharynx. 
By George H. Carpenter, B.Sc.Lond., M.R.I.A., Professor of 
Zoology, and Mabel C. MacDowell, A.R.C.Sc.I., Research Student, 
Royal College of Science, Dublin. (With Plates 35-37 and 5 Text- 
figures) ....... 373 
Nerilla an Archiannelid. By Edwin £. Goodrich, F.R.S., Fellow of 
Merton College, Oxford. (With Plates 38-41) . . . 397 
On a Freshwater Medusa from Rhodesia. By Charles L. Boulenger, 
M.A., Lecturer on Zoology in the University of Birmingham. (W ith 
Plate 42 and 2 Text-figures) ..... 427 
Studies in the Experimental Analysis of Sex. Part 8. — On the 
Effects of the Removal and Transplantation of the Gonad in the 
Frog (Rana fuse a). By Geoffrey Smith, M.A., and Edgar 
Schuster, M.A., D.Sc., Fellows of New College, Oxford. (With 
Plates 43-46) . . . . .449 
With Title, Contents, and Index to Vol. 57. 
