QUARTERLY JOURNAL 
OF ref er briny £3 - 
MICROSCOPICAL SCIENCE. 
EDITED BY 
Sm RAY LANKESTER, K.C.B., M.A., D.Sc., LL.D., F.R.S., 
HONOKAKY FELLOW OF EXETER COLLEGE, OXFORD; CORKKSPONDENT OF THE INSTITUTE OF ¥RANCE, 
AND OF THK IMPERIAL ACADEMY OF SCIKNCES OF ST. PETERSBURG, AND OF THE ACADEMY 
OF 8CIENCKS OF PHILADKLPHIA, AND OF THE ROYAL ACADEMY OF SCIKNCES 
OF TURIN; FORKIGN MEMBER OF THE ROYAL SOCIETY OF SCIENCES OF 
GOTTINGEN, AND OF THE ROYAL BOHEMIAN SOCIRTY OF SCIENCES, AND 
OF THK ACADEMY OF THE LINCEI OF ROMK, AND OF THR AMERICAN 
ACADEMY OF ARTS AND SCIENCES OF BOSTON; ASSOCIATR OF THR 
ROYAL ACADEMY OF BELGIUM: HONORARY MEMBER OF THE 
NEW YORK ACADEMY OF SCIKNCKS, AND OF THER 
CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OF 
THE ROYAL PHYSICAL SOCIETY OF EDIN- 
BURGH, AND OF THE e 
BIOLOGICAL SOCIRTY OF PARIS, AND OF THK CALIFORNIA ACADEMY OF SCIENCES OF SAN FRANCISCO, AND 
OF THK ROYAL ZOOLOGICAL AND MALACOLOGICAL SOCIETY OF BELGIUM, 
CORRESPONDING MEMBER OF THE SENKENBERG ACADEMY OF FRANKFURT-A-M; 
FOREIGN ASSOCIATE OF THK NATIONAL ACADEMY OF SCIENCES, U.S., AND MEMBER OF THE 
AMERICAN PHILOSOPHICAL SOCIETY 3 
HONORARY FELLOW OF THE ROYAL SOCIETY OF EDINBURGH} 
LATE DIKRKCTOR OF THE NATUKAL HISTORY DEPARTMENTS OF THE BRITISH MUSKUM: LATE PRESIDENT OF THR 
BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCF; LATK FULLEKIAN PROFKSSOR OF 
PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN « 
LATR LINACRE PROFESSOR OF COMPARATIVE ANATOMY AND FELLOW OF MERTON COLLEGE, OXFORD) 
EMERITUS PROFESSOR OF ZOOLOGY AND COMPARATIVE ANATOMY IN UNIVERSITY COULEGE, UNIVERSITY OF LONDON. 
WITH THE CO-OPERATION OF 
ADAM SEDGWICK, M.A., F.RS., 
PROFESSOR OF ZOOLOGY AND COMPARATIVE ANATOMY IN THE UNIVERSITY OF CAMBRIDGE 
SYDNEY “dl 2 HICKSON, (M.As ies: 
BEYKR PRKOFESSOK OF ZOOLOGY IN THE UNIVERSITY OF MANCHESTER, 
AND 
K. A. MINCHIN, M.A., 
PROFESSOR OF PROTOZOOLOGY IN THE UNIVERSITY OF LONDON, 
VOLUME 53.—New SeERIEs. 
GMith Aithoqraphic Plates and Cext-Fiqueres 
ORD ON : 
J & A. CHURCHILL, 7, GREAT MARLBOROUGH STREET. 
1909. 
