192 NAIADES. 
structure of the pistillum to Ruppia, it is among the lowest 
of the order i organisation. This same, or another species 
occurs at Dadur in ditches, but if the same it attains a larger 
size. The real situation of the flowers with respect to 
the leaves, setze and spathoid membranes obscure, and will 
require more patient looking into than I can now give, and 
better means of observation than I possess at present. 
The most curious part of the structure is the embryo, aud 
especially the very long cotyledone, and the manner in which 
itis packed, analogous something to Nelumbuim, and to 
which extreme length and consequent induplication the first 
progress is presented by Ruppia itself. 
The character of the genus may be thus stated. 
Flores monoici, (sexus distincti vel aggregati) vaginis fo- 
liorum inclusis, 
Mas. solitarius stamen unicum, nudum vel membranum ob- 
longe plane stipatum ? 
Fem. 3-4 aggregata, pedunculo brevi immulato, tubo 
spathoideo semi-inclusa. Ovarium subsessile. Stigma maxi- 
mum cordatum. Ovulum pendulum.  Carpella vel capsula 
subsessilia oblonga subindurata, indehiscentia, Semen pen- 
dulum curvatum. Embryo radicule maxime clavata, Coty- 
ledone subulato longissimo induplicato. 
Herba immersa habitu et foliis Кирріг, floribus inconspi- 
uis, | 
Farther examination leads me to consider it doubtful that 
neither the male flower, or female is truly axillary, if so, the 
male is, and the female is not, and in that case the oblong spa- 
thoid body does not belong to the flowers of either sex, but 
is analogous or rather akin to the vaginiform sheath, which, as 
it is sometimes present without any leaf, is I think to be con- 
sidered as a species of bud-scale, analogous to that of Dipte- 
rocarpez etc, In this view it is rudimentary; because the 
axis is not often elongated in more than one direction. 
When two leaves exist, two scales should be present as is 
generally the case, and this intervening between the flower 
