Evans: Hep aticae of Puerto Rico 171 



The lobules in both species are normally bidentate, and the 

 perianths are five-carinate with smooth or nearly smooth keels. 

 The lobule in A. Auberiana, however, is subrectangular in outline 

 rather than ovate, the keel being nearly straight, and the marginal 

 teeth tend to be larger and more pronounced than in A. viridis- 

 sima. The leaf-cells also offer certain points of distinction, 

 although they average about the same in size. In A. Auberiana 

 the local thickenings of the walls are rarely confluent, the trigones 

 are mostly in the form of equilateral triangles with straight sides, 

 and the intermediate thickenings are oval or circular in outline. 

 In A. viridissima, on the other hand, the thickenings are more 

 frequently confluent, the trigones show a strong tendency to be 

 tnradiate, with rounded and often constricted rays, and the inter- 

 mediate thickenings show a similar tendency to be rectangular, 

 with rounded ends. A. Auberiana is further characterized by the 

 lobules of its perichaetial bracts ; these are much smaller than in 

 A. viridissirna and are usually adnate to the lobes throughout 

 their entire length. Although the differences which have just 

 been enumerated are slight, they seem to be constant. 



Another allied species is Lejeunea florentissima Spruce, which 

 the writer would keep distinct from A. Auberiana. This species 

 is more robust than A. viridissirna, and the lobes of the leaves 

 are more falcate ; the keel of the lobule is parallel with the free 

 margin, but both are more or less curved; the trigones in the leaf- 

 cells are similar to those in A. Auberiana but are better developed, 

 the sides of the triangles being convex rather than straight. The 

 subfloral innovations in L. florentissima are usually soon floriferous 

 and the perianths are thus crowded together in a cymose cluster; 

 in A. viridissirna the arrangement of the perianths is much more 



"regular. 



LEUCOLEJEUNEA 



The characters of the genus Lencolejeunea, recently segregated 

 by the writer from Archilejeunea, have already been so fully dis- 

 cussed * that it hardly seems necessary to enumerate them here. 

 Five species are definitely known at the present time, the generic 

 type being Z. clypeata (Schwein.) Evans, a widely distributed 

 species in the eastern United States. The only representative of 



*See Torreya 7 : 225-229. 1908. 



