OONTEJNTS. 



CONTENTS or No. 137, N.S., JULY, 1893. 

 MEMOIRS : 



PAGE 



On the Morphology and Physiology of the Brain and Sense Organs 

 of Limulus. By William Patten, Ph.D., University of North 

 Dakota, Grand Porks, U.S.A. (With Plates 1—5) . . 1 



The Structure of the Pharyngeal Bars of Amphioxus. By W. 

 Blaxland Benham, D.Sc.Loud., Hon. M.A.Oxon., Aldrichian 

 Demonstrator of Comparative Anatomy in the University of 

 Oxford. (With Plates 6 and 7) . • • • ^7 



Ou the Perivisceral Cavity of Ciona. By A. H. L. Newsteab, 

 B.A., late Scholar of Clirist's College, Cambridge. (With 

 Plate 8) 119 



The Early Stages in the Development of Distichopora vio- 

 lacea, with a Short Essay on the Fragmentation of the Nucleus. 

 By Sydney J. Hickson, M.A. Cantab, et Oxon., D.Sc.Lond., 

 University Lecturer on the Morphology of Invertebrates; Pellow 

 of Downing College, Cambridge. (With Plate 9) . . 129 



CONTENTS OF No. 138, N.S., SEPTEMBER, 1893. 



MEMOIRS 



Studies on the Comparative Anatomy of Sponges. By Arthur 

 Dendy, D.Sc, Fellow of Queen's College, and Demonstrator and 

 Assistant Lecturer in Biology iil the University of Melbourne. 



(With Plates 10—14) 159 



h 



