12 MR. 8. D. HAVILAND: REVISION OF THE NAUCLEES. 
sessile fruit and filiform interfloral bracteoles. Uncaria pedicel- 
lata and U. ferrea, the two nost dominant Malayan forms, enter 
Tenasserim, and U. pedicellata has even got to Pegu and Cochin 
China; but there is only one peculiar species (U. macrophylla) 
in Asia with pedicelled fruit and no interfloral bracteoles ; all 
the seven other Asian species have sessile fruit and filiform 
bracteoles. "Two species with sessile fruit and filiform bracteoles 
have been found in Sumatra (U. homomalla and U. Roxburgh- 
iana), and Korthals gives Borneo as a locality for the latter; 
yet the species in Malasia which have pedicelled fruit and no 
bracteoles number more than twenty. The species in Tropical 
America number only two; they resemble the Asian forms in 
having interfloral bracteoles, but their fruits are pedicelled. To 
the Westward, Uncaria seems to stop at the Himalayan region, 
and not even to pass down the Peninsula of India; a variety 
of a Malayan species, U. dasyoneura, is found in Ceylon, but 
this perhaps has reached Ceylon without passing through India. 
The changes it has undergone are quite distinct, but not sufficient 
to give it specific rank. This practical absence of Uncaria from 
Southeru India and Ceylon is most remarkable. In Madagascar, 
the Comoro Islands, and Tropical Africa a form is found whieh, 
though variable, does not readily fall into distinct species. It 
is very distinct from any of the other forms, but is more allied 
to the Malayan and American than to the Asian forms. Re- 
turning again to Malasia, it must be noticed that Malpina 
contaius representatives of most of the Malayan forms, and 
seems to be now quite the headquarters of the genus. 
Next to the genus Uncaria the genus Mitragyna stands most 
distinct, although the last to be founded, and still sometimes 
confounded with Adina. It consists of the only species with 
truly valvate corolla-lobes, it consists of the only species with 
truly mitrate stigma, it consists of the only species with ovules 
imbricating upwards on a pendulous placenta, it consists of 
the only species whose fruit-capsules open at the top. Its 
seeds are quite distinct, being not elongate but subovate. 
As in Uncaria, the endocarp becomes coriaceous and separates 
from the outer wall of the fruit-capsule. There are inter- 
floral bracteoles as in Adina and Cephalanthus, but they are 
much more numerous and broader, they quite surround each 
flower, and are nearly glabrous excepting on the margins. 
In one or two species the calyx is truncate, in others the 
