Sample XII, from Jolpabuchil, contained relatively 
small amounts of poorly preserved pollen and great quan- 
tities of carbonized debris, which might perhaps have 
been re-deposited material. Recognizable tracheids of 
the sort described by Muller (1959) as re-deposited from 
Eocene sediments in Venezuela were frequently en- 
countered. Pollen grains included some Rhizophora of 
uncertain affinity. The presence of marine fossils indi- 
cates probably an offshore environment. 
SUMMARY AND CONCLUSIONS 
Pollen from 12 rock samples from Chiapas, Mexico, 
either from strata containing amber or immediately ad- 
jacent to them, were studied. These samples do not vary 
greatly in lithology, ranging from calcareous siltstone or 
silty shale to calcareous sandstone. They are all from 
strata considered to be latest Oligocene or earliest Mio- 
cene in age and represent apparently a relatively small 
interval of geological time. The palynological data indi- 
cate development of mangrove vegetation of considerable 
complexity at or close to the site of deposition of the 
amber. The most important elements of the vegetation 
from the standpoint of the pollen record were members 
of the genus Rhizophora, in all probability representing 
several species of different ecological preferences. A]- 
though only one other genus known to be a member of 
the New World mangrove association today (i.e., Pelli- 
ciera) was encountered, the possible presence of others 
is not precluded. As studies by Muller (1959), van der 
Hammen (1963) and Spackman et al. (1964) have indi- 
cated, other mangroves such as Laguneularia and Cono- 
carpus may be present, but only Rhizophora and Avicen- 
nia pollen commonly occur in abundance in recent sedi- 
ments. Until more careful studies of the delimitation of 
different mangrove species and their pollen are made, 
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