118 CONTRIBUTIONS TO THE 
cases out of ten, or even in a much greater proportion, these 
numbers are a safe and useful guide. 
MALPIGHIACEA. 
In the determination of the plants of this order, I have scrupu- 
lously followed the admirable monograph of Prof. A. de Jussieu, 
where the genera are so well established that there are but few 
cases where a fair specimen, even without the fruit, may not be 
satisfactorily referred to its genus. The identification of species is 
much more difficult, especially where the specimens do not show both 
flower and fruit. In some cases I have been assisted by authentic 
specimens determined in my herbarium by M. de Jussieu himself; in 
others, by his accurate and elaborate descriptions : the chief doubts 
are in regard to some of the old-established species, which M. de 
Jussieu has considered as sufficiently well characterised by previous 
authors, and to which he has unfortunately not added his own 
diagnosis or descriptions. 
1. Byrsonima verbascifolia, Rich. A. Juss. Malp. p. 26.—Dry 
savannahs, British Guiana, Schomb. lst Col. n. 91, 2nd Col. 
n. 259 (447); Surinam, Hostm. n. 1296. (Cayenne, Aublet and 
others.) All the Guiana specimens I have seen belong to the 
common variety figured by Aublet, with very cottony leaves, and 
the ovary thickly covered with hairs. 
* 2. B. eriopoda, DC. A, Juss. Malp. p. 26. (Cayenne? DC.) 
9. B. rugosa, sp.n. foliis obovatis basi acutis bullato-rugosis 
supra glabratis v. ad venas pulverulentis subtus rufo-tomentosis 
et ad costam hispidis, stipulis petiolo longioribus, calyce 10-glan- . 
duloso, antheris parce hispidis, connectivo ultra loculos producto, 
ovario apice hirsuto.— British Guiana, Schomb. 2nd Col. n. 870 
(1319). 
Rami crassi, novelli pilis rufis dense hispidi, adulti glabrati. 
Folia 5-7 poll. longa, 2-8 poll. lata, apice sepius breviter acumi- 
ata, basi longiuscule angustata in petiolum brevem, supra glabra, 
nisi ad basin cost; mediæ pilulis minutis pulverulenta, nitida, 
inter venas bullata, margine revoluta, subtus undique tomento brevi — 
. rufescentia, costa venisque primariis valde elevatis et uti petiolus — 
