306 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 
the varietal name of Delilei, on account of a structural peculiarity 
which will appear further on. 
I].—Tue Genus anv rts Divisions. 
The genus gives its name to the natural order Naiadacee, which 
is allied to the Potamogetonacee, but systematists are by no means 
agreed as to the respective limits of either family. Willdenow 
separated the group to which N. graminea belongs from Naias 
ups of Naias and Caulinia 
into Naias Linn. There is no doubt, however, that each of these 
again and again to this memoir, and I cannot speak too highly of 
the help derived from it. ps Big 
Dr. Magnus gives the following diagnoses of the two subdivisions 
of the genus, viz.: : 
‘* § Eunasas Asch.—Spine-teeth chiefly on the stem and backs 
cellular spaces by two to three layers of parenchyma-cells. Leaf 
furnished with a small-celled epiderm, which rises very sharply 
f. 
backs of leaves. Flowers in most species moneecious (? im alt). 
of cellular tissue. Conducting bundles of the stem divided from 
the intercellular spaces by a layer of parenchyma-cells; leaf without 
the small-celled epiderm.”_« Beitrage,’ pp. 55, 56. 
The plant which forms the subject of this notice belongs to the 
Section Caulinia, and its synonymy and principal book-references 
are the following :— 
T1].—Synonymy or tHe Puant. 
Najas graminea Delile, Flore de l’Egypte. Mémoire sur les plantes 
qui croissent spontanément en Egypte; par Alire Raffeneau 
Delile, p. 1. Flore Aigyptiace illustratio No. 874, p- 75. 
Explication des planches, p. 282, pl. 50, fig. 8. _ 
Chamisso, Aquatice quedam diverse affinitatis. Linnea, vol. 
iv., 1829, pp. 502-3. 
Se ee ee eee 
* ‘Mémoires de l’Académie Royale des Sciences de Berlin, 1798, classe de 
Philosophie Expérimentale,’ page 87. 
