Explanations ok Vlatks. 305 



LYRODICTYA, Hall. 



Page 170. 

 (See Plate LVI.) 



LyRODICTYA (?) BURLINGTONENSIS, Hall (sp.). 

 Page 165. 



Figure 6. A view of the original specimen, which is a fragment of a broadly 

 expanded frond with strong bundles of vertical spicules, compacted 

 at the base but diffused toward the apertural portion. The reticula- 

 tion is uniformly fine. 

 Burlington group (Yellow sandstones). Burlinijton, Iowa. 



