312 



Alexander ir. Evans, 



or nearly so, broadly ovate, about 1.5 mm. long and 1.2 mm. wide, slightly 

 or not at all decurrent antically, shortly decurrent posticall)', antical margin 

 more or less revolute (on well-developed leaves), slightly outwardly curved, 

 entire, postical margin strongly outwardly curved from the short and narrow 

 decurrent portion, sharply dentate-spinose, apex broad and rounded, simi- 

 larlj' dentate-spinose ; total number of teeth mostly ten to twelve, unequal, 

 usually two to five cells long and one to three cells wide at the base, teeth in 

 the apical region tending to be larger than the others ; leaf-cells plane, aver- 

 aging about 20 u in the apical region, 25 X 20 _u in the middle, and 35 X 20^ 

 at the base, walls with large triangular trigones usually with bulging sides, 

 and (especially toward the base) occasional oval intermediate thickenings, 

 coalescence between thickenings rare except near the margin ; cuticle minutely 

 striolate-verruculose : remaining parts not seen. (Fig. 6.) 



Figure 6. — Plagiochila strioi.ata Evans 

 A. Leaf, dissected from the stem, X 17. B. Cells from the middle of a 

 leaf, X 300. C. Tooth from near the middle of the postical margin of a leaf, 

 X 225. The figures were drawn from the type specimen. 



Although roughened cuticles are frequently found in many genera 

 of the Hepaticae they have rarely been associated with definite 

 species of Plagiochila. Stephani, however, has recently described two 

 South American species in which this peculiarity occurs. These are 

 P. asperi folia Steph., collected by Puiggari and Ule in Brazil, and 

 P. verrucosa Steph., collected by Funck and Schlim in Venezuela. 

 Unfortunately these species are known to the writer from description 

 only, but are evidently distinct from P. striolata. The first is somewhat 

 more robust, the leaves being about 2 mm. long. It is further dis- 

 tinguished by its obliquely truncate leaves with three apical spines, 

 the anterior one being usually much larger than the others. The 

 second species is still larger, the leaf-cells are only 12 /< wide at the 

 apex and only 36 x 12 // in size at the base, while the cuticle is 

 coarsely verruculose. The spines in this species are furthermore said 

 to show a distinct increase in size not only toward the apex but also 

 toward the postical base. 



