ARTICLE IV. ON A NEW SHOVELNOSE STURGEON FROM 



THE MISSISSIPPI RIVER. BY S. A. FORBES and R. E. page 



RICHARDSON. (4 Plates.) May 15. 1005 37-44 



Introductory 37 



Parascaphhhyiicliiis. gen. nov 38 



Parascaphirhynchus albiis, sp. nov 38 



Tabular comparison of Parascapbirhyticlius albiis and Scaphirliynchns 



platorhynchns 40 



Key to Parascaphirhynchus and related Genera 41 



Bibliography 42 



ARTICLE V. NOTES ON* SPECIES OF NORTH AMERICAN OLI- 

 GOCH.-ETA. V. THE SYSTEMATIC RELATIONSHIPS OF 

 LUMBRICULUS (THINODRILUS) INCONSTANS (SMITH). BY 



FRANK SMITH. December 26, 1005 45-51 



Comparison with Tricliodrilits and Litmbriciilns varicgatits 45 



Albumen Gland 45 



Positions of Spenniducal Pores and Gonads 46 



Setae 46 



Vascular System 47 



Spennathec:e 47 



Atrium and Penis 48 



Less important Characters 48 



Lnmbriculus 49 



variegatus 49 



inconstans 50 



Summary SO 



Literature cited. . 51 



ARTICLE VI. A CATALOGUE OF THE MOLLUSCA OF ILLINOIS. 



BY FRANK COLLINS BAKER. (1 Map.) September. 1906... 53-136 



Introductory 53 



Exptanatory 53 



Acknowledgments 53 



Topography 54 



Literature 55 



New Species and Varieties described from Illinois 56 



Molluscan Fauna of Illinois discussed 57 



Fluviatile Mollusks 57 



Terrestrial Mollusks 59 



Numerical Comparison of Illinois Mollusks with those of other States. 59 



Geographical Distribution 61 



Systematic Catalogue of Species 63 



Bibliography 124 



Index 134 



