TABLE OF CONTENTS. 



Volume XVI. 



Papers read before the Academy and published in this vol- 

 ume. A list of those read and not published, or read only by 

 title appears below. 



HERBERT BOLTON. PAGE 



The Lancashire Coal Field of England 224 



C. M. CHILD. 



The Maturation and Fertilization of the Egg of Arenicola marina (figs. 



1-8 ) 387 



BASHFOED DEAN. 



Note on the Ventral Armoring of Dinichthys 57 



On a New Species of Edestus, E. Lecontei, Dean 61 



BASHFORD DEAN AND F. B. SUMNER. 



The Spawning Habits of the Brook Lamprey, Petromyzon Wilderi, at Van 

 Cortlandt Pond 321 



p. H. DUDLEY. 



Investigations of the Undulations in Railway Tracks by the Author's 

 Track Indicator, and the Reduction of Two-thirds of their Amount 

 in the Past Fifteen Years by the Use of the Author's Stiff Railway 

 Sections 139 



BRADNEY B. GRIFFIN, B.SC. 



Adaptation of the Shell of Placuanomia to that of Saxidomus, with Re- 

 marks on Shell Adaptation in General 77 



N. R. HARRINGTON. 



Nereids from Puget Sound (Pacific Coast) which Live Commensally 



with the Hermit Crab, Eupagurus armatus 214 



N. -R. HARRINGTON AND B. B. GRIFFIN. 



Notes on the Distribution, Habits and Habitat of Some Puget Sound In- 

 vertebrates 152 



MISS F. R. M. HITCHCOCK. 



Notes on the Atomic Mass of Tungsten 332 



