CONTENTS. 



CONTENTS OF No. CXXII, N.S., JUNE, 1890. 



MEMOIRS : PAGE 



The Embryology of a Scorpion (Euscorpius italicus). By 

 Malcolm Laurie, B.Sc, Falconer Fellow of Edinburgh Uni- 

 versity. (With Plates XIII— XVIII) . . . .105 



On the Morpliology of the Compound Eyes of Arthropods. By S. 

 Watase, Fellow of the Johns Hopkins University. (With Plate 

 XIX) 143 



On the Structure of a Species of Earthworm belonging to the Genus 

 Diachaeta. By Frank E. Beldam), M.A., Prosector to the 

 Zoological Society of London. (With Plate XX) . . 159 



Hekaterobranchus Shrubsolii, a New Genus and Species of 

 the Family Spionidse. By Florence Buchanan, Student of 

 University College. (With Plates XXI and XXII) . . 175 



An Attempt to Classify Earthworms. By W. B. Benham, D.Sc, 

 Assistant to the Jodrell Professor of Zoology in University 

 College, London ....... 201 



CONTENTS OE No. CXXIII, N.S., AUGUST, 1890. 

 MEMOIRS : 



On the Origin of Vertebrates from Arachnids. By William Patten, 

 Ph.D., Professor of Biology in the University of North Dakota, 

 Grand Forks. (With Plates XXIII and XXIV) . .317 



On the Origin of Vertebrates from a Crustacean-like Ancestor. By 

 W. H. Gaskell, M.D., F.R.S. (With Plates XXV, XXVI, 

 XXVII, and XXVIII) 379 



The Development of the Atrial Chamber of Amphioxus. By 

 E. Ray Lankester, M.A., LL.D., F.R.S., and Arthur Willey, 

 Student of University College. (With Plates XXIX, XXX, 

 XXXI, and XXXII) 445 



