CONTENTS OF No. 201. -New Series. 



MEMOIRS 



PAGE 



On tlie Parietal Sense-organs and Associated Structures in the New 

 Zealand Lamprey (Geotria australis). By Artiiue Dendy, 

 D.Sc, P.L.S., F.Z.S., Professor of Zoology in King's College (Uni- 

 versity of London). (With Plates 1 and 2) . . .1 



Studies in Spicule Formation. V. — The Scleroblastic Development 

 of the Spicules in Ophiuroidea and Ecliinoidea, and in the Genera 

 Antedon and Synapta. By W. Woodland, Demonstrator of 

 Zoology, King's College, London. (With Plates 3 and 4) .31 



Studies in Spicule Formation. VL — Tiie Scleroblastic Development 

 of the Spicules in some MoUusca and in one Genus of Colonial 

 Ascidians. By W. Woodland, Demonstrator of Zoology, King's 

 College, London. (With Plate 5) . . . .45 



A Preliminary Consideration as to the possible Factors concerned in 

 the Production of the various Forms of Spicules. By W. AYooD- 

 LAND, Demonstrator of Zoology, King's College, London . 55 



On Neurosporidium cephalodisci, n. g., n. sp., a Sporozoon 

 from the Nervous System of Cephalodiscus nigrescens. By 

 W. G. lliDEWOOD, D.Sc, Lecturer in Biology at St. Mary's 

 Medical School, University of London ; and H. B. Fantham, 

 B.Sc, A.B..C.S., University College, London; Demonstrator in 

 Biology at St. Mary's Medical School. (With Plates 6 and 7) . 81 



Gametogenesis and Fertilisation in Ne mat us ribesii. By L. Don- 

 caster, M.A., late Mackinnon Student of tlie lloyal Society; 

 Lecturer in Zoology in the University of Birmingham. (With 

 Plate 8) . . . . . .101 



The Molhiscan Radula: its Chemical Composition, and some Points 

 in its Development. By Igerna B. J. Sollas. (With Plate 9) . 115 



Observations on Tooth-Development in Ornithorliyuchus. By J. T. 

 Wilson, Professor of Anatomy, University of Sydney, N.S.W., and 

 J. 1*. Hill, Jodrell Professor of Zoology, University College, 

 London. (With Plates 10—12) . . .137 



