Mr. J. Miers on the genus Brachistus. 261 
«stones are only swallowed by frugivorous birds, which require 
them to triturate their food, and are never found in the gizzards 
of the Raptores.” Hence it was argued, that the Dodo, which is 
known to have had stones in its stomach, could have no affinity to 
Raptorial birds. Dr. G. Dickie of Aberdeen has however called 
my attention to a passage in Sir J. C. Ross’s Antarctic Expe- 
dition, which shows that the above generalization, though un- 
doubtedly true in general, admits, like all rules, of an exception. 
It is there mentioned (vol. ii. p. 159) that stones were usually 
found in the stomachs of the Aptenodytes Forsteri, to the amount 
of two to twenty lbs. weight. This is certainly a remarkable 
fact in the case of a piscivorous bird, and indicates some pecu- 
liarity in its habits which it would be desirable to clear up. Do 
any of the fucivorous Fish swallow pebbles to help digestion, 
and can the Penguin have thus acquired these foreign matters at 
second hand? But whatever be the cause of this habit in the 
Penguin, it does not affect the argument as to the remoteness of 
the Dodo from the Raptorial birds. 
XXXII.—Coniributions to the Botany of South America. 
By Joun Mizrs, Esq., F.R.S., F.L.S. 
[Continued from p. 146. ] 
BRACHISTUS. 
A PARTICULAR group of plants has been before alluded to under 
this name (ante, p. 144), most of which have been referred to 
Witheringia by Prof. Kunth, and from which genus I have shown 
that they differ by having a campanular calyx generally with an 
almost entire margin, which does not enlarge with the fruit, by 
a much smaller berry and other characters. They are also di- 
stinet from Aenistus by the calyx being generally entire on the 
margin, rarely 5-toothed, and not having the five strong prominent 
nervures which give to the calyx of the latter genus the appear- 
ance of an almost pentangular tube: they differ also in the much 
shorter tube of the corolla, a more rotate border, more dilated 
stamens arising from a triangular expansion at the base, as in 
Hebecladus and Saracha; their flowers are considerably less in 
size, and they have smaller berries, which exhibit a very thin 
membranaceous dissepiment, not thickened in the middle by the 
confluence of the placentz, as in Witheringia, Acnistus, Iochroma, 
Saracha, &c.; the placentz on the contrary, originating from a 
central line in the middle of the dissepiment, are thin and 
‘slender, projecting for a short distance at right angles into the 
cavity of the cell, and then become furcated, continuing mem- 
