CONTENTS 
Final Report on the Study and Appraisal of Mussel Resources in 
Selected Areas of the Upper Mississippi River—N. M. Grier, 
It eres erp yen a PY Ne ae OP are a a 1 
Corrections in Botanical Nomenclature—Oliver A. Farwell ~-------- 33 
Notes on Birds of the Vicinity of Washington, Pa.—Dr. and Mrs. 
ee ROR LOL a. ar ete eS oe Ee i ee 35 
Seasonal Dimorphism in Arisaemae Triphyllum.—Theo. Holm _---- 41 
The Evolution of the Tools and Implements—William D. Johnson __ 49 
Nomeclatoral Notes on Certain American Plants—II.—Homer D. 
GPT ace REE Sp GEOL E <R) SE ORE He ee Dire nove aie ee ee ee ey Se 61 
The Geography of Bird Study—0O. A. Stevens _--------------+---- 65 
Spring and Summer Birds of Northfield, Minnesota. 1921—J. W. 
TOTO CIE ore Bee SN a GO) Se he nee ee ee ee 73 
Bird Migration Record Made at Notre Dame, Ind., Sept. 9 to 
November 30, 1920—Brother Alphonsus, C. S. C, -------------- 81 
The Histological Structure of the Gills of Najades, with Special 
Reference to the Histology of the Groove Along the Edge of 
the-wnnercGill— rai sds Bushee ee Coe 8 oe ee a 89 
Notes on Alabama Plants—W. Wolf, O. S. B. _----....-------------- 104 
Observation on the Rate of Growth of the Shell of Lake Dwelling ~ 
Fresh Water Mussel—N. M. Grier, Ph. D. --___--------------- 129 
Euglena Viridis (Ehrenberg)—Sister M. Ellen  ___~-....--_-------- 149 
Evidences of a Differential Death Rate of the Sexes Among Ani- 
TRIS Ve Ge Chee Pe Psy ne oe ee eo ee 153 
An Amateur Wild Flower Bed—O. A. Stevens ____----------~---...--- 164 
Birds of Watertown, Wisconsin—Brother Alphonsus, C. S. C. ------ 172 
Notes Relative to Species of Gambusia in the United States—S. W. 
Re err ee hee ee eects te ee tee es Se tes ee Fe ee 175 
The Birds of Floyd County, lowa—Carroll L. Fenton ~-----~~ 189, 230 
The First Robin—Brother Alphonsus, C. S. C. ~--------....-_-----+--- 209 
Nortonechinus, a Devonian Echinoid—Carroll L. Fenton, and 
SISTEM A ANTES i OULOTS rae a as im ee ee 219 
The Marchantiaceae of Sinsinawa Mound—Sister M. Ellen ~-_----~- 222 
Birds in the Vicinity of Rosary College, River Forest, Illinois. 
os ia TAY CGR 12: el CNSR ERS RAE Se = es SERN RP A aS SO 224 
Birds of Notre Dame, Indiana—Brother Alphonsus, C. S. C. ~--257, 283 
Birds of Bankson Lake, Michigan—Brother Alphonsus, C. S. C. ..--260 
Botanical Gleanings in Michigan—Oliver A. Farwell ~-----------.... 263 
On the Naiades of Long Island, New York—N. M. Grier, Ph. D. ----281 
Book Reviews—Carroll L. Fenton ~-----.--_--_.-_--___ 39, 69, 88, 127 
