CONTENTS. 



Co< kerell, T. D. A. Some new Bees of the genus Perdita > 11 



Ellis, J. B. Notes on some specimens of Pyrenomycetes in the Schwein- 



itz Herbarium 20 



Rhoads, Samuel N. Descriptions of new Mammals from Florida and 



Southern California 32 



Leonard, Charles Lester, M. D. On a new Method of Studying 



Cell Motion 38 



Rhoads, Samuel N. New Subspecies of the Gray Fox and Say's Chip- 



munk 



Harris, Gilbert D. New and otherwise interesting Tertiary Mollusca 



(Plates 1-9) 4 ' 5 



Kennedy, William. Tbe Eocene Tertiary of Texas, east of the Brazos 



River 89 



Ryder, John A. An arrangement of the Retinal Cells in the Eyes of 



Fishes partially simulating Compound Eyes 161 



Ryder, John A. The true Nature of the so-called "Nettle-Threads" 



of Paramcecium * 67 



Ortmann, Arnold E. A Study of the Systematic and Geographic Dis- 

 tribution of the Decapod Family Crangonidse Bate 173 



Walter, Emma. Does the Delaware Water Gap consist of two River 



Gorges 198 



Pilsbry, H. A. and E. G. Vanatta. New species of the Genus Ceriou. 206 



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