CONTENTS. 
I. Binary Families in a Triply connected Region, with Especial Reference to Hyper- 
PAGE 
geometric Families. 
By D. R. Curtiss 1 
II. Brygos: his Characteristics. By Oliver Samuel Tonks 
61 
III. The Spectrum of Hydrogen in the Region of Extremely Short Wave-Length. By 
Theodore Lyman 
121 
IV. Lunar and Hawaiian Physical Features Compared. By William H. Pickering 
149 
V. High Electromotive Force. By John Trowbridge 185 
VI. Contribution toward a Monograph of the Laboulbeniace.e. Part II. Bv 
Roland Thaxter 217 
