576 



ALEXANDER W, EVANS 



Fig. V Metzget'ia niidtifo7-niis Evans. 



A. Part of a thallus, showing a distinct costa, X 50. B. Ecostate portion of a broad thallus, 

 X so. C. Part of a narrow tlialliis, showing a reversion from a cosiate to a ecostate condition, 

 X SC. D. Female branch, X 100. E. Female branch, showing a short vegetative proHferation, 

 X 100. F. Ecostate gemma still attached to parent thallus, X 100. G. Part of a gemma, 

 showing change from a costate to an ecostate condition, X 100. B was drawn from a Masa- 

 fuera specimen (no. 55), and the remaining figures from the type-specimen. 



thing is true of many costate gemmae, especially if the costae are rudimentary. 

 The gemmae usually remain attached until they are i cm. or more in length; 

 their width and the average measurements of their cells are somewhat less than 

 in the case of ordinary thalli. No cases of germination have been observed. 



