162 Evans: Hepaticae of Puerto Rico 



closely in the characters derived from the lobes of the leaves, 

 from the underleaves, and from the bracts and perianths that it 

 would be superfluous to describe these organs in detail for Pty- 

 chocoleus. There are also no essential differences in color, in 

 general habit, or in cell-structure. The lobules of the leaves, how- 

 ever, are much more variable in Ptychocoleus than in Brachiolejeunea, 

 especially with respect to the number of teeth on the free margin. 

 Certain species develop as many as four or five teeth, others only 

 two (figure 5), while in still others the margin is quite entire 

 except for the apical tooth. In the position of the hyaline papilla 

 the genus agrees with Brachiolejeunea, except for the fact that it is 

 sometimes so much displaced that it is difficult to determine 

 whether it is distal or proximal to the apical tooth, while on the 

 other hand it may arise directly from a marginal cell. The position, 

 however, is usually constant for a given species. The branching, 

 so far as observed, always conforms to the Lejeunca type. 



The genus shows but little relationship with other Lejeuneae 

 which lack subfloral innovations. In Lopholejeunea the keels of 

 the perianth are winged and variously toothed or laciniate, the 

 lobules are built up on a different plan, and the local thickenings 

 in the cell-walls are different. In Caudalejeunea the perianth is 

 trigonous, its keels are normally winged and toothed, the plants 

 are different in habit, and the leaf-cells show very numerous inter- 

 mediate thickenings. In Bryopteris the female branch is much 

 shorter, the perianth is again trigonous, the leaves and under- 

 leaves are sharply toothed, and the whole habit, general appear- 

 ance, and cell-structure are different. 



Ptychocoleus polycarpus (Nees) Trevis. 



Jungermannia polycarpa Nees, in Marti us 



1833. 



agmicoma poly carp 



Fl. Bras, i' : 350 



1845. 



Jour. Bot. 5: 389. 1846. 



Ptychocoleus polycarpus Trevis. Mem. 1st. Lomb. III. 4: 405 



1877. 



Amaz. et And. 116. 1884! 



■olcjeunea polycarpa Schiffn. i 

 fern, i 3 : 128. ' 1895. 



poly 



