Evans: HEpaticAr or Puerto RIco 13 
substratum, in much the same way as in Stictolejeunea squamata. 
_Microphyllous branches are only occasionally present, and the 
modifications which they exhibit are not very strongly marked. 
Their leaves bear a strong resemblance to those found at the base 
of anormal branch and apparently retain some of the juvenile char- 
acters of the species. The lobes of these leaves are sometimes 
~ only 0.15 mm. long ; they are destitute of hyaline cells and tend 
to assume a suberect position. The lobules and underleaves on 
microphyllous branches are smaller than usual but otherwise 
normal. Branches of this character are more frequent in crowded 
tufts and are perhaps due to a lack of illumination. 
The perianth in JV. catenu/ata is subject to a great deal of varia- 
tion. When well-developed the lateral auricles and the large 
postical swelling extend for a considerable distance beyond the 
beak, and it sometimes appears as if the latter were an outgrowth 
from the antical surface of the swelling. Under these circum- 
stances there is frequently a short and low fold in the middle of 
the postical keel (rrcurE 12) and a similar fold in the middle of 
the antical surface. When poorly developed the apex of the 
perianth is truncate and the beak forms the most projecting part, 
no lateral auricles being formed. When this is the case the pos- 
tical keel is usually distinctly two-angled, and there are no sup- 
plementary folds on either surface. Between these two extremes 
there are many intermediate conditions. The wings along the lat- 
eral keels forma very inconstant feature of the perianth (FIGURE 1). 
Neurolejeunea Breutelii (Gottsche) 
Lejeunea Breutelit Gottsche, in G. L. & N. Syn. Hep. 324. 1845. 
Symbiezidium Breutelii Trevis. Mem. R. Ist. Lomb. III. 4: 403. 
I : 
Lejeunea (Neuro-Lejeunea) Breuielii Spruce, Hep. Amaz. et And. 
84. 1884. 
Léjeunea (Ceratolejeunea) Breutelii Steph. Hedwigia 27: 283. 1888. 
Ceratolejeunea Breutelii Schiffn. in Engler & Prantl, Nat. Pflanzen- 
fam. 1°: 125. 1895. 
Dark olive-green or brownish, somewhat glossy, loosely tufted : 
stems 0,1 mm. in diameter, with few rhizoids, irregularly pinnate, 
the branches obliquely to widely spreading, variable in length and 
rarely subdivided, usually with smaller leaves than the stem and 
