558 



ALEXANDER W. EVANS 



Fig. I. Riccardia breviramosa (Stepli.) Evans. 



A — C. Pans of male thalli, X 8. D. Transverse section of the main axis, X lOO. E, F. Trans- 

 verse sections of primary branches, X lOO. G. Tip of a primary branch, with secondary branches, 

 X 40- H Marginal part of main axis in transverse section, X lOO. I. Transverse section of a 

 metzgerioid branch, X 140. J. Transverse section of a stolon, X 140. K. Ventral surface of a 

 primary branch, X 100. A— E, G. and I — K were drawn from no. 21; F and H, from no. 25. 



wings are less crispate, and the trigones are less pronounced. These slight 

 differences, however, are merely quantitative and would hardly be sufficient to 

 justify a specific separation, even if the specimens were more abundant. 



