356 Mr. COLEBROOKE on Boswellia 
ripe seed in a cell have not hitherto been observed in either of 
the described species. 
The remarkable character of multifid and intricately folded 
cotyledons, which will be noticed, recurs in certain other plants 
of the same natural order, and especially in one which it is my 
purpose to describe in this essay, and which exhibits three-lobed 
contortuplicate cotyledons. It was first delineated solely from 
the flower; the fruit not having ripened on the trees where I 
observed the blossom. Dr. Wallich, having been more fortunate 
than myself in this respect, has since furnished me with a par- 
ticular description of the ripe fruit, and has proposed the name 
of Bursera serrata for my plant. I had taken it, while unac- 
quainted with its fruit, for an Ailanthus. 
It certainly is akin to the Marignia of Commerson, which 
Lamarck introduced into the genus Bursera, with the specific 
name of obtusifolia* ; and which his continuator Poiret in one 
place remarks to have much affinity with Gertner’s Dammara, 
and in another says it appears to be the samet. . 
Gartner himself, identifying his plant, of which the specimen 
was received from the Isle of Mauritius, with the Dammara ni- 
gra of Rumphius, indigenous in the Molucca Islands, remarked 
its near affinity to Amyris, and thought it possibly a genuine 
species of that genus}. But it has the intricate foldings of the 
cotyledons which are remarked in Bursera serrata. 
As the two genera of Amyris and Bursera are at present con- 
stituted, a botanist may well be still at a loss to which of them a 
new plant of the family is to be referred. The variable features 
of Bursera gummifera, and the early inaccurate descriptions of 
it, have led systematic writers to assign an essential character to 
the genus constructed on its type, which is very loose and uncer- 
* Encycl. ii. 768. + Enc. Supp. ii. 447 & 812. 
t Fruct. et Sem. ii. 103. 
tain ; 
