374 Evans : New West Indian Lejeuneae 



small underleaves are characters which 7! dilatata shares with 

 certain species of Prionolejeunea, but of course its five-keeled per- 

 ianth would at once exclude it from this genus. 



Of the three species of Trachylejeunea already recorded from 

 the West Indies, T. prionocalyx (Gottsche) Schififn.* is especially 

 close to T. dilatata. This species is apparently endemic to Cuba. 

 The original material was collected by Wright, but additional 

 specimens were lately found by Underwood and Earle on El 

 Yunque Mountain, near Baracoa. Both species show an abrupt 

 dilation of the lobe, thin cell-walls, an absence of ocelli, an autoi- 

 cous inflorescence, and subfloral innovations. In T. priono- 

 calyx, however, the plants are smaller than in T. dilatata, the 

 leaves rarely exceeding 0.3 mm. in length, the margins of the 

 lobes are crenulate rather than denticulate, and the roughness is 

 restricted to the keels of the perianth, even the leaf-lobes being 

 smooth except for the marginal crenulations. Here again the 

 roughness of the keels is due to projecting cells, but these are 

 longer than in T. dilatata, their walls are thicker, and their ex- 

 tremities are rounded rather than conical ; the effect produced is 

 one of greater roughness. The male spikes in T. prionocalyx are 

 short and show only two or three pairs of bracts. 



The two other West Indian species of Trachylejeunea are T. 

 Aquarius (Spruce) Evans f and T. Spruce ana Steph.J The first 

 of these was originally described from Brazilian material but is 

 now known also from both Puerto Rico and Cuba ; the second is 

 known only from Guadeloupe, where the type specimens were 

 collected by L'Herminier. In T. Aquarius the plants are more 

 robust than in T. dilatata, the leaves are ocellate at the base, the 

 leaf-cells have large and conspicuous trigones, and the roughness 

 affects not only the lobes and lobules but also the surface of the 

 perianth between the keels, especially in the upper part. In tne 

 perianth the roughness is due to convex and uniformly thickened 

 cell-walls, while in the leaves there is a large median wart arising 

 from each cell. Even the underleaves in this species sometimes 

 show a few scattered warts along the margin. In T, Spruceana 



* Bot. Jahrb. 23 : 592. //. j 5 . / S-12. 1897. . 



tHep. Araaz. et And. 185. 1884. See also Evans, Bull. Torrey Club 3° ' 

 561. //. 22. /. 11-22. 1903. 

 J Hedwigia 35 : 138. 1896. 



