THE NAUTILUS. 29 



Cypraea spadicea Gray. Area grandis B. & S. 



Ranella ealifornica. Dosinia ponderosa. 



Fomaulax undosus Wood. Pecten subnodosus. 



Con us californicus Conr. Fusus dupetithouarsi Kiener. 



Semele decisa Conr. Drillia penicillata Cpr. 



Uvanilla regina Stearns. Monoceros muricatum Brod. 



Venus fordii Yates. Crucibulum imbricatum. 



Triton gibbosum. Purpura biserialis Blve. 



Macron aethiops. Venus unclatella Sby. 



Cymatium corrugatum Lam. Cassis sp. 



Conus gradatus Mawe. Oniscia sp. 



For several miles along the cliffs on the southwest coast of Cedros 

 extends a well marked stratum about a foot in thickness of Lucina 

 californica, and very strangely not another marine species was 

 found with them. 



In about ten fathoms off Palm Spring on the east coast we suc- 

 ceeded in making one haul of the dredge with the following results : 

 Hemicardium biangulatum. Nassa insculpta. 



Pecten latiauritus. 



A number of small or difficult species collected on the trip remain 

 to be identified. A list of them will appear later. Dr. Pilsbry has 

 in press an illustrated paper on the Helices of the Micrarionta group 

 collected. 



As the weather was unfavorable for a continued southerly cruise, 

 we reluctantly headed the " Flyer " for home where we arrived just 

 four weeks from the time of starting. 



THE UNIONE FAUNA OF THE GREAT LAKES. 



BY BRYANT WALKER, SC. D. 



{Continued from page S3.) 



The distribution of these two species, Unio complanatus and U. 

 gibbosus (fig. 2), in a general way, shows the relative position the 

 Atlantic and Mississippian faunas occupy in the region of the Great 

 Lakes. Of course there are variations in the range of individual 

 species, but these, on the whole, do not interfere with the general 

 proposition to be discussed in this paper. 



