CON T E N T S. 
TRANSACTIONS OF THE SOCIETY. 
PAGE 
I. A New Calculating Machine. By Edward M. Nelson, F.R.M.S. (Fig. 1) . . 1 
II. On the Male of Rhinops vitrea. By Charles F. Rousselet, F.R.M.S. 
(Plate I.) 4 
III. Second List of New Rotifers since 1889. By Charles F. Rousselet, F.R.M.S. 10 
IV. Presidential Address : Suggestions as to Points connected with the Micro- 
scope and its Accessories still needing Improvement. Resume of the 
Anatomy of Bdella. By A. Michael, F.L.S., &c 97 
V. On a New Mechanical Stage (Figs. 11-15. By Edward M. Nelson, 
President R.M.S 185 
VI. On the Development and Structure of Dental Enamel. By J. Leon 
Williams, D.D.S., L.D.S., F.R.M.S. (Plates I r.-V.) 261 
VII. The Limits of Species in the Diatomacese. By Thomas Comber, F.L.S., 
F.R.M.S 455 
VIII. A Contribution to the Freshwater Algse of the South of England. By 
W. ' West, F.L.S., and G. S. West, A.R.C.S. Communicated by A. W. 
Bennett, F.L.S., F.R.M.S. With Appendix by A. W. Bennett, F.L.S., 
F.R.M.S. (Plates VI. and VII.) 467 
SUMMARY OF CUBRENT RESEARCHES 
RELATING TO ZOOLOGY AND BOTANY (PRINCIPALLY INVERTEBRATA AND 
Cryptogamia), Microscopy, &c., including Original Communications 
from Fellows and Others.* 16, 107, 182, 188, 255, 269, 351, 512 
ZOOLOGY. 
VERTEBRATA. 
a. Embryology. 
Heape, W. — Menstruation and Ovidation of Mcicacus rhesus 16 
Floderus, Matts — Amitotic Nuclear Division in the Egg of the Hedgehog .. .. 17 
Lange, J. — Oogenesis in the Mouse 17 
Janosik, J. — Division of Ovarian Ova 17 
Fischel, A. — Embryonic Variations and Growth 17 
Tims, H. W. Marett — Tooth- Genesis in Canidse 18 
Kukenthal, W. — Dentition of Manatee 18 
Tiemann, H. — Development of Nostrils in Mammals 19 
Meves, Fr. — Spermatogenesis in Salamander 19 
Flemming, W. — Influence of Light on the Pigmentation of Salamander Larvae .. 19 
Neal, H. V. — Segmentation of Nervous System in Squalus Acantliias 19 
Schneider, G. — Genital Ducts of Teleosteans 20 
Dean, Bashford — Larval Development of Amia calva 20 
Kopsch, Fr. — Blastoderm Margin in Salmonidse 21 
Sobotta, J. — Syncytium in Cleavage of Belone acus 21 
* In order to make the Contents complete, the papers printed in the ‘ Transactions ’ 
and the notes printed in the ‘ Proceedings ’ are included here. 
