165 
markable for its very irregular and incompletely developed cortex, 
the cells of which are short and numerous ; the intermediate (sec- 
ondary) tubes are often suppressed wholly or in part, their places 
filled by the spreading cells of the adjacent series; the spines are 
very short and pointed (almost conical), The stipules are well 
developed but short, as compared with the lowest nodes of the 
leaves, upper row .425 mm. long; lower row .250 mm. long. 
Leaves about 10, consisting of only 4 or § segments, including the 
tip, which may be 2-celled The lowest naked node is often very 
long, as shown in Fig. 5, but usually about 5 times as long as its 
diameter, (1.5 mm. long, 0.365 mm. in diameter. The lowest 
node is usually fertile. Bracts, anterior about two-thirds the length 
of the sporophydium, posterior very short. Coronula short, of 
somewhat diverging cells; nucleus about 0.650 long by 0.360 
broad, with 12-1 3 strie. Antheridium 0.315 mm, in diameter. 
This species seems to be referable to Ch. inconstans A. Br., but : 
_to differ from the two forms, both belonging to the West Indies, — 
C. Erstediana and C. Cruegeriana, by the large nucleus, as well as 
the characters of the stem and leaves; the irregular cortex of the 
Present gathering may not prove to be constant in this variety. 
In Plate rgr, fig. 1, plant natural size; figs. 2-5 X 25; fig. 7 | 
nucleus X 50, x 
NEW SPECIES OF NITELLA. 
The species now to be described supplement the first fascicle 
of the second (systematic) part of my Characeze of America, re- 
cently issued. | 
NITELLA MEXICANA sp. nov. 
Nitella monarthrodactyla, furcata, homceophylla, monoica, — 
Symnocarpa, apiculata; group of WV. flerilis Ag. et 
Stem large, .730 to 1.098 in diameter, verticils of 8 leaves; 
leaves about .585 in diameter, once divided; terminals 2-3, about 
-365 in diameter ; sporophydia aggregated (usually) 13: 1 SUG 
ber at node of leaf ; nucleus .275 long, .230 broad, with 5 promi- 
Ment striz; membrane of the spore very minutely granular. 
ntheredium -245 in diameter. suvets 
This robust species, collected by Mr. Pringle in slow-flowing 
__ Streams in Mexico, appears at first sight to belong to N, flexilis 
_ Ag., to which it is clearly allied ; it differs, however, by its mu 
* 
