CONTENTS. 



PAGE 



I. A Revision of the North American Species of the Genus 



Oxijtropis, DC. By AsA Gray 1 



II. Notes on some North American Species of Saxifraga, By Asa 



Gray 8 



III. A Contribution to our Knowledge of Paleozoic Arachnida. By 



Samuel H. Scudder 13 



IV. On the Development of some Pelagic Fish Eggs. — Preliminary 



Notice. By Alexander Agassiz and C. O. Whitman . 23 



V. The External Morphology of the Leech. By C. O. Whitman 76 



VI. On the Anatomy and Histology of Aulophorus Vagus. By 



Jacob Eeighard . 88 



VII. Descriptions of New Species of Camharus ; to which is added a 

 Synonymical List of the known Species of Camharus and 

 Astacus. By Walter Faxon 107 



VIII. A Method of Measuring the Absolute Sensitiveness of Photo- 

 graphic Dry Plates. By William H. Pickering . . . 159 



IX. On the Reduction of Camphor to Borneol. By C Loring 



Jackson 163 



X. Dictyoneura and the Allied Insects of the Carboniferous 



Epoch. By Samuel H. Scudder 167 



