24 Evans : Hepaticae of Puerto Rico 



pearance due to the frequent confluence of the local thickenings, 

 leading to an obliteration of the pits. The bracts and perianths are 

 very similar in the two species, but the bracteoles afford another 

 difference. In P. macroloba these are distinctly bidentate at the 

 apex, the teeth being acute and often connivent ; in P. Schwaneckei 

 the bracteoles are either undivided or shortly or irregularly biden- 

 tate with blunt teeth. In P. macroloba , finally, microphyllous 

 branches are rare, and many plants fail to develop them altogether. 



For assistance in the preparation of this paper the writer is 

 especially indebted to Professor Lindau, of Berlin, and Herr 

 Stephani, of Leipzig. Through their kindness it has been possible 

 to examine the type specimens of Lejeunea Berteroana, Pycnolejeu- 

 nea Schwaneckei and several of their allies. Lejeunea decidna, L. 

 versifolia and L. emarginidiflora were based on specimens distrib- 

 uted in exsiccatae, and these have also been studied by the writer. 

 The type specimens of L. pliyllobola and L. line at a have not been 

 consulted. 



Yale University. 



