CONTENTS. 
PAGE 
A Eevision of the Genus Alepidea, Delaroche. By R. Dummer. 
(Plate I.) 1 
Positive Electrical Variation in Isolated Nerve. By W. A. Jolly. 
(With five Text-figures) 23 
Description of a New Species of Sting-Ray {Trygon) from South 
Africa. By J. D. F. Gilchrist, D.Sc, F.R.S.S.Af. (Text-figure) 33 
A Short Note on the Occurrence of a Leucocytozoon Infection. 
Host : The Ostrich. By J. Walker, M.R.C.V.S. (Plate II.) . 35 
Valency and Chemical Affinity. By James Moir, M.A., D.Sc, 
F.R.S.S.Af 39 
The Rainfall on Table Mountain. By Thomas Stewart, M.Inst.C.E. 41 
Addendum to Revised List of the Flora of Natal. By J. Medley 
Wood . 47 
Tidal Phenomena at Inland Boreholes near Cradock. By Andrew 
Young, M.A., B.Sc, F.G.S., F.C.S. (Plates III.-VI., and five 
Text-figures) 61 
Descriptions of Some New Batrachia and Lacertilia from South 
Africa. By John Hewitt, B.A., and Paul A. Methuen, F.Z.S. 
(Plate VIL) 107 
Notes on Namaqualand Bushmen. By Miss L. Currle. (With 
Additional Notes by D. Peringuey, F.R.S.S.Af.) ... 113 
Some New or Little Known South African Succulents. Part V. 
By R. Marloth, Ph.D., M.A., F.R.S.S.Af. (Plate VIII.) . . 121 
The Blizzard of June 9-12, 1902. By A. G. Howard, M.S.A., 
Cape Town. (Three Text-charts) 129 
The Leaf-spots of Bichardia albo-maculata, Hook. By W. T. 
Saxton, M.A., F.L.S. (Three Text-figures) .... 135 
On the SaUvary and Mouth Glands of the Nudibranchiata. By 
T. F. Drbyer, B.A., Ph.D. (Six Text-figures) .... 139 
A List of South African Lacertilia, Ophidia, and Batrachia in the 
McGregor Museum, Kimberley; with Field-Notes on Various 
Species. By J. Hewitt and J. H. Power .... 147 
Note on Double Alternants. By Thomas Muir, LL.D., F.R.S. . 177 
