Mr. J. Miers on some of the Heliotropiex. 123 
two opposite bipartite parietal placente, each fork bearing a 
single ovule, as in Agiphila and Amerina. If these figures 
be correct, as there is no reason to doubt, these species cannot 
belong to Ehretia, or else the characters of the genus have 
been erroneously defined, and the tribe itself has been placed 
in a wrong family. ‘These discrepancies show that we have 
yet much to learn in regard to the Hhretieew. If we hold 
Beurreria still in doubt, as well as Amerina, for the reasons 
before given, there will remain only Ehretia itself to represent 
the tribe; and this offers so many anomalous characters that 
DeCandolle considered it must ultimately be divided into se- 
veral genera, of which he traced the outlines in Beurreria, 
Carmona, Xerodema, and Menais. Xerodema has been shown 
to be identical with Rhabdia, a Brazilian genus minutely and 
accurately described by Prof. von Martius in his ‘ Nova 
Genera,’ and since figured by Sir Wm. Hooker (Icon. 828). 
This construction, of a 1-locular ovary, with two opposite 
2-lamellar placentee bearing an ovule on each of their reflected 
margins, and a fruit with four nucules, each with a longitu- 
dinal open slit leading into two cells, is quite at variance with 
the structure that has been attributed to Hhretia and its allied 
genera. I will offer some observations upon Lthabdia and 
Cortesia under separate notices. 
The following is a synopsis of the genera of the Helio- 
trope — 
1, Fructus baccatus; albumen distinctum. 
A. Pyrenze 2, singulz 2-loculares. 
a. Embryo rectus; stamina inclusa; stylus brevis; 
stigma latum, breviter 2-lobum.............. Tournefortia. 
B. Pyrenze 4, singule 1-loculares. 
6. Embryo lunatim curvatus; corollz laciniz subu- 
late; stamina inclusa; stylus longiusculus ; 
stigma majusculum, apice conico, piloso ...... Messerschmidtia. 
2. Fructus exsuccus; albumen distinctum, aut nullum. 
C. Pyrene 2, singulee 2-loculares; stamina inclusa. 
c. Stigma breve, vix divisum; albumen nullum.... Helophytum. 
d, Stigma magnum, elongatum, profunde 2-fissum ; 
STUNTIST, CUSGUTIC LUI, . ueie e evs sree su0'e ats a Wiss chat Cochranea. 
D. Pyrenz 2, singulz 2-loculares. 
e. Stamina longe exserta; stylus tenuis; stigma te- 
MOR) 2-8 LLIN 35.5091 aisha oy. payee bleh «ae oldies me . Tiquilia. 
E. Pyrenee 4, singule 1-loculares. p 
f. Antherz apice papilloso coherentes; stylus brevis 
aut subnullus; stigma magnum; flores interdum 
sOlifnMsen axallares*.1) 7.0) \els see Fas ahees we.» Sehlerdenia, 
g. Anthere glabree, oblongze, liberze ; stylus medio- 
cris; stigma magnum; flores in spicas longas : 
curvatas terminales, 1-laterales.............- Heliotropium. 
h. Anthere glabree, globose, liber ; stylus simplex, : 
2-fidus; flores axillares, solitarill ............ Coldenia, 
