1 6 Evans : Hepaticae of Puerto Rico 



veloped, but even under these circumstances the relatively large 

 leaf-cells will usually serve to distinguish the species. 



CYSTOLEJEUNEA 



The systematic position of Lejeunea lineata has long been a 

 matter of uncertainty. Spruce first referred it to the subgenus 

 Macro-Lejeiinea, basing his opinion on the simple female branch 

 and the perianth without keels. He afterwards followed Stephani 

 and transferred it to Cheilolejetuiea, apparently on account of the 

 flattened perianth, but remarked at the same time that the species 

 had certain characters in common with Tr achy lejeunea* Schiffner 

 also followed Stephani at first and considered the plant a Cheilole- 

 jennea ; afterwards he apparently reverted to the original view of 

 Spruce and listed the species as Macrolejeimea lineata. This solu- 

 tion of the problem, however, by no means satisfied him, and he 

 noted that the vegetative structure agreed in many respects with 

 what is found in Euosmolejeunea. Still later he replaced the species 

 in Cheilolejeunea.^ 



It will be seen from the above that Lejeunea lineata has certain 

 points of agreement with four recognized genera of the Lejeuneae, 

 but that the balance of opinion is in favor of placing it in Cheilole- 

 Jeunea. Its peculiar lobule, however, should apparently exclude 

 it not only from this genus, as emended in the present paper, but 

 also from the other three genera to which it has been compared. 

 It becomes necessary, therefore, to propose a new genus for its 

 accommodation. 



CYSTOLEJEUNEA gen. nov. 



Plants rather robust, firm in texture, not glossy : stems pros- 

 trate, loosely adherent to the substratum, sparingly and irregularly 

 branched, the branches widely spreading, not microphyllous : leaves 

 imbricated, the lobe widely spreading, convex and reflexed at the 

 broad apex, entire or nearly so ; lobule strongly inflated, ellipsoidal 

 or broadly ovoid, with strongly arched keel, free margin strongly 

 involute throughout, apical tooth scarcely evident, hyaline papilla 

 proximal, reflexed, sinus exceedingly short ; leaf-cells convex with 

 large trigones ; ocelli none : underleaves distant, subrotund, cuneate 

 at the base, bifid with sharp divisions : Q inflorescence borne on a 



*BulL Soc. Bot. de France 36: clxxxii. 1889. — See also Jour. Linn. Soc. Bot. 

 30: 331. 1894. 



f Conspect. Hepat. Archip. Indici 256. 1898. 



