44 IOWA ACADEMY OF SCIENCES. 



AQUATIC OR SUB- AQUATIC FORMS. 



Limncea reflexa Say. Reported (2) 



Limncea ijalustris Mull. Reported (2) 



Other Limncea (8) 567 183 750 



Physa gyrina Say (9) 1 1 2 



Physa heterostropha Say (9) 



Bulinus hypnorum (L) Binn. Reported (10) 



Planorhis parvus Say 5 5 



Planorbis trivolvis Say. Reported (11) 



Segmentina armigera (Say) H. & A. Ad. Reported (12) 



Valvato tricarinata Say. Reported (2) 



Campeloma subsolidum Anth Reported (13) 



Pisidium sp. (14) 2 2 



Unio undulatus Barnes 6 6 



Vnio rubiginosus Lea 5 5 



Unio pusttdosus Lea (15) 1 1 



Total aquatic forms 570 201 771 



TABLE II. 



List of fossil molluscs from the " Post-pleiocene deposits"' ^^ 



Zonites fuUginosus (Griff.) Binn 



Zonites intertextus Binn. 



Zonites inornatus (Say) Biun. 



Zonites gularis (Say) Binn. 



Patida soUtaria (Say) Binn. ''. 



Slenotrema stenotrema (Fer.) Try. 



Triodopsis palliata (Say) Binn. 



Triodopsis obstricta (Say) Binn. 



Triodopsis inflecta (Say) Binn. 



Mesodon elevata (Say) Binn. 



Mesodon exoleta (Binn.) Try. 



Helicina orbiculata Say ^^ 



TABLE III. 



List of Unios from modified Loess submitted by Mr. Bain. 

 These are all from near the mouth of the Broken Kettle, Plymouth 

 county, Iowa. 



Unio anoxontrides Lea. 

 Unio donaciformis Lea. 

 Unio elegans Lea. 

 Unio 2)ustidosits Lea. 

 Unio rubiginosus Lea. 

 Unio undulatus Barnes. 



1. J. E. Todd, Proc. Am. A. A. S., Vol. XXVII. p. 6, from southwestern Iowa. 



2. G. C. Swallow, Geol. Sur. of Mo., Vols. I and II, p. 315, from Missouri. 



3. The eggs vary slightly in size. The smaller agree exactly with eggs of modern 

 P. striateUa. The larger m \y belong to another species; 



4. R.E. Call, Oa the Loess and Assorted Deposits of Des Moines, pp. 14 and 17; from 

 Des Moines Iowa. F. M. Witter, Rep. U. S. Geol. Sur. Vol. XI, p. 47. ■ 



5. These lots include Pupa perdodon, Vertigo ovata, etc., the greater part consisting 



