174 Evans : Hepaticae of Puerto Rico 



sent by Mr. M. B. Slater, that it is quite indistinguishable from the 

 widely distributed Lejeitnea conferta Meissn. Although placed by 

 recent writers in Archilejeunea, L. conferta cannot be considered 

 congeneric with the typical members of this genus, and there seem 

 to be excellent reasons for maintaining Anoplolejeunea as distinct. 

 Spruce compares it with his subgenus Platy-Lejeunea, but it is 

 evidently much more closely related to the genus Leiicolejeunea. 



The plants grow in depressed mats and are either pale- or dark- 

 green in color with neither glossiness nor pigmentation. The pros- 

 trate stem is copiously and irregularly branched, some of the 

 branches being similar to the stem while others are ascending and 

 distinctly microphyllous (plate 8, figure 9). The normal leaves 

 are imbricated, the convex lobe spreading widely and showing a 

 rounded apex and entire margin. The leaf-cells are plane or 

 nearly so, with small trigones and occasional intermediate thicken- 

 ings (figure 16), and ocelli are sometimes present at the base of 

 the lobe (figure 17). 



The lobule when normally developed is more complicated than 

 in most of the other genera of the Lejenneae. It is ovate-oblong 

 in outline and forms a strongly inflated water-sac with an arched 

 and convex keel (figure 9). From a relatively short base it is 

 abruptly dilated and becomes suddenly contracted in the outer 

 part. The dilated portion, bounded by the rounded and entire 

 free margin, forms a volute with about one and a half turns (fig- 

 ure 14). This comes into contact with the lobe, thus enclosing 

 the water-sac, but the margin itself, together with a considerable 

 extent of the lobule, lies free within the sac and can be distin- 

 guished by careful focusing from below. The lobule develops no 

 apical tooth, the free margin being directly continuous with the 

 sinus; just at the junction of the two, however, a cell may be 

 observed which is a little larger than its neighbors and which 

 doubtless represents the terminal cell of the lobule, homologous 

 with the apical tooth of other Lejeuncae (figure 18). At the 

 beginning of its course the sinus is also strongly revolute but 

 straightens out abruptly and passes into the postical margin of the 

 lobe at the end of the keel. The hyaline papilla is marginal and 

 arises from the terminal cell, usually at its junction with the first 

 cell of the sinus ; it may therefore be regarded as distal in posi- 



