100 Fern Allies. [ ZOE 
studied in the field, noting the differences that appear as the water 
lowers and the plant become terrestrial. 
MARSILIA MINUTA F ournier, Bull. Soc. Bot. France, 1880, 329. © 
Morales, San Luis Potosi (Schaffner), hitherto referred to JZ. vestita; 
Chihuahua, 1886 (Pringle), sterile plants which doubtless belong 
here; Guadalajara, 1889 (Pringle, Nos. 2424 and 2632, the latter a 
peculiar growth of plants, showing in natant forms transitions towards 
M. picta Fee). The well-fruited specimens of Mr. Pringle (No. 2434) 
show this species to be clearly distinct from either AZ. vestifa or M. 
tenutfolia, with which it has hitherto been confused. 
_ MARSILIA MACROPODA Engelm. — Matamoras, Mexico, 1888 
(Pringle, No. 1975). This species had hitherto been found only in 
‘Texas and New Mexico. 
MarsIia Mexicana A. Br. Cusihuiriachic, state of Chihuahua, 
Mexico, 1888 (Pringle, No. 2007); San Jorge, Baja California, 1889 
(Brandegee). 
? MARSILIA POLYCARPA Hook & Grev. A sterile plant commu- 
nicated as JZ. picta Fee, San Luis Potosi, Mexico (Schaffner) and 
hitherto referred to MW. vestita, is perhaps a form of JZ. polycarpa, as 
suggested by Baker.* Leaves with similar sculptured forms (said 
to be produced by some aquatic animal) are found in natant forms 
of M. Mexicana, minuta and quadrifolia. 
PILULARIA AMERICANA A. Br. California: Antioch, 1884 (Bran- 
degee); San Diego, 1884 (Orcutt); May, 1889 (Brandegee); Colusa 
Co., April, 1889 (Brandegee). Mexico: Santo Tomas Mission, Baja 
California, 1886 (Orcutt). The original station was Santa Barbara, + 
from whence we have seen no specimens. It is also reported by 
Prof. E. L. Greene from Suisun.{ Californian specimens agree well 
with forms cultivated at Berlin from Chili by Al. Braun. It is doubt- 
less wide-spread, and from its inconspicuous form just as widely over- 
looked. It will be of interest to know more of its distribution since 
Nuttall collected it in Arkansas. : 
AZOLLA CAROLINIANA Willd. California: Santa Cruz Mountains, 
August, 1888 (Underwood). Arizona: 1887 (Lemmon). Mexico: 
San Miquelita, San Luis Potosi (Schaffner); Morales, San Luis Po- 
tosi (Schaffner, communicated as 4. Mexicana); Orizaba, March‘ 
1890. (Phila. Acad, Expl. in Mexico, No. 113). 
*Handbook of Fern Allies, 139. tBotany of California, ii, 352. 
tPittonia, ii, 106 (1890), : 
