268 Mr. Bentuam’s Review of the Order of Hydrophyllez. 
ovarium, as far as it goes, appears to be the best character that can be taken 
for generic distinctions. In order to show how far any others may be brought 
in aid, I shall proceed to examine them separately. 
In general habit and foliage, the distinction between Hydrophyllee and 
Borraginee is not always so marked as appeared from the species first known. 
Several Phaceliee and Eutoce have exactly the habit of Echium, Cynoglossum, 
or Anchusa; and some of the latter genus have the leaves constantly entire, 
. although the “ folia composita vel alte lobata” do run through the greater 
number of species. Some Nemophile may be compared to Asperugo, which 
has frequently opposite leaves (though always entire) and the same fragile 
trailing stem. The rough hispid hairs are the same in both tribes. As amongst 
one another, Hydrophyllum, Emmenanthe, and Nemophila have each a peculiar 
habit; but Eutoca and Phacelia are so much blended together in this respect 
that it would be difficult to assign any character derived from the vegetative 
organs peculiar to either genus. 
The gyrate inflorescence of Borraginee may be very readily observed in 
Hydrophyllum, Phacelia, Eutoca, Emmenanthe, Ellisia, and in Nemophila au- 
rita and phacelioides; but in the remaining Nemophile it is (as in Asperugo) 
axillary, and can therefore only serve as a specific, not as a generic character, 
and in the general description of the order it must be considered in the light 
of a subsidiary, not an essential character. 
The calyx is usually the same as in the majority of Borraginee, inferior, 
persistent, and deeply 5-cleft, but with this particularity, that in some in- 
stances the sinuses (as in some Campanulacece) are furnished with reflexed 
appendages, resembling the erect divisions of the calyx in form, but smaller in 
size. As shown by M. Alphonse De Candolle in his Monographie des Campa- 
nulées, p. 11, these divisions do not indicate any organic modification in the 
composition of the calyx, but are merely owing to the prolongation of the 
united lateral nerves of two adjoining sepals, as is rendered evident by the 
nervation of the calyx of Ballota, Marrubium, Leucas, and other Labiate with 
more than five teeth to their calyx. The character derived from this cir- 
cumstance must consequently be inconstant, and have little or no relation to 
general habit, as may be observed in Hydrophyllum, where it would separate 
H. appendiculatum from its close allies H. canadense and virginicum; and if 
