IOWA ACADEMY OF SCIENCES. lOT 



Fig. 1. Transection of head through auditory region at time auditory 

 involution is just beginning. 



Fig. 2. Similar section of-embryo of the age of the one shown in Figs. 8 

 and 4. 



Fig. 5. Similar section of somewhat older embryo. 



Fig. 6. Similar section of embryo shown in Fig. 7. 



Fig. 8. Similar section of embryo shown in Fig. 9. 



Fig. 10. Similar section of embryo shown in Fig. 11. 



Figs. 1, 2, 5, 6, 8 and 10 are magnified 50 diameters; Figs. 3 and 4 five and 

 one-third diameters; Figs. 7 and 9 four diameters; Fig. 11 three diameters. 



AN INSTANCE OF THE PERSISTENCE OF THE DUCTUS VENOSUS 

 IN THE DOMESTIC CAT. 



BY H. W. NORRIS. 



After injecting with starch-mass through the right femoral vein it was 

 found that the entire arterial system of the cat was filled with starch. 

 Investigation showed the presence of good sized functional ductus venosus 

 through which the arterial and venous systems communicated. The indi- 

 vidual possessing this peculiarity was, in life, troubled with what is vulgarly 

 called " fits," whatever that may have been in this particular case. I should 

 be loth to admit any relation between "fits" and the presence of afunc- 

 tional ductus venosus without more extended data. 



ADDITIONAL NOTES ON IOWA MOLLUSCA. 



BY B. SHIMEK. 



About five years ago the writer published an annotated list of Iowa Mol- 

 Z?^sca* under the title "The Mollusca of Eastern Iowa." Material has been 

 secured since by which many of the species have been traced across the 

 entire State, and which also throws much additional light on the synonymy 

 of some of the species. 



Without an attempt at a thorough and complete revision of the former 

 list a few notes on species heretofore mentioned are presented, and a num- 

 ber of species which have been collected or recognized in the State since the 



•Bulletin from the Lab. of Nat. Hist, of the State University of Iowa, Vol. I, No. 1, 



November, 1888. 



