IOWA PTERIDOPHYTA {Continued. 



BY B. SHIMEK. 



The writer's recent visit to Dubuque and Clayton 

 counties, Iowa, a part of the time in company with Messrs. 

 Anderson and Nelson of the Dubuque High School, resulted 

 in interesting additions to the collection of Iowa Pteri- 

 dophyta in the Herbarium of the State University, which 

 were received too late for insertion in the main paper on 

 pp. 145-170 of this Bulletin. The region in which these 

 additional collections were made lies in Liberty township, 

 Dubuque county and Millville township, Clayton county, 

 and includes the interesting gorge known as Pine Hollow, 

 together with smaller ravines of a similar nature which are 

 tributary to the Little Turkey river. The collections were 

 made May 10-13, 1901. A list of the additional material, 

 with references to the main paper, is here given: 



Equisetum arvense L. (p. 154). 



Common, and still fruiting in both counties. 



Equisetum pratense Ehrh. (Insert on p. 154). 



Sterile specimens of this species were quite common on 

 rocky slopes along Pine Hollow creek in both counties. 

 The species has not been reported from this State. 



Equisetum robustum A. Braun. (p. 155). 



Very common on lower ground in both counties. A few 

 specimens are in fruit. 



Equisetum hyemale L. (p. 155). 



Quite common in low sandy soil along Pine Hollow 

 creek in Dubuque county. None fruiting. 



