519 
a portion of Hampe’s original plant is to be found in Herb. Under- 
wood. All the specimens from the Rocky Mountain region and 
the Pacific coast that have been referred to Porella pinnata belong, 
so far as we have seen them, to Porella rivularis. 
2. PoRELLA SwArTzIANA (Web.) Trevis. Mem. r. Ist. Lomb. 
Ill: @ 3-407. 4877: 
Jungermannia Swartziana Web. Prod. 18. 1815. 
Madotheca Swartziana Lindenb. G. L. N. Syn. Hep. 271. 1845. 
Sordid-green or slightly fulvous, dull, opaque: stems procum- 
bent, irregularly pinnate or subbipinnate, 3-5 cm. long; branches 
obtuse, mostly short : dorsal lobes of leaves subimbricate, circum- 
volute when dry or spreading, ovate, obtuse, I-1.7 mm. x .7—1.2 
mm., entire or slightly repand, inferior margin decurved or sub- 
inflexed, occasionally a little undulate-crisped, the leaf-cells with 
prominent trigones ; ventral lobes narrowly falcate or linear-oblong, 
erect, or commonly with the falcate apex introrse and appressed 
to the underleaves, flat with plane margins or somewhat concave 
ventrally, obtuse, ‘rarely acuminate, entire or subrepand above, 
bearing at the base 1-3 cilia on the inner margin and sometimes a 
single cilium on the outer, not decurrent, .5—.85 mm. x .08—.17 
mm., length %4-% the width of the dorsal ; underleaves oblong, 
erect-appressed, rarely exceeding stem in width, obtuse, truncate, 
or emarginate-repand, margins plane, entire above, ciliate-dentate 
at base, subdecurrent. . 
In low ravines, Opelousas, Louisiana (Rev. A. B. Langlois, no. 
228 and, in part, no. 529). 
The Louisiana plants agree very Soacly with a West Indian 
specimen of P. Swartziana in Herb. Underwood. Mexican speci- 
mens referred to this species differ in several respects. Weber 
supposed his original (which we have been unable to locate) to 
have been collected in Jamaica. We have seen no perianths or 3 
branches and these parts are not described by authors. 
3. Poretta Wataucensis (Sulliv.) Underw. in herb. 
Madotheca Porella var. ? Sulliv. Musc Allegh., no. 265. 1845. 
Madotheca ee | Sulliv. in A. Gray, Man. Bot. 700. 
1856. [2d ed.] | 
Similar to Porella seri of which it is perhaps a variety —dif- 
