of humid evergreen or of seasonally dry semi-deciduous 
forest types on the Pacific slopes in Central America. 
It is common along coastal plains and rivers, and grows 
also on beaches and sandy ridges that interdigitate with 
lagoons. Hymenaea Courbaril varies in the amount of 
resin produced under natural forest conditions at various 
sites. lt appears to produce larger quantities where con- 
ditions favor a more rapid growth rate. Resin may ac- 
cumulate in the soil around the base of the tree in large 
amounts (Noriega, 1918: Record and Hess, 1943) and 
trom there can easily be transported into either marine or 
brackish-water sites in or near which mangroves fre- 
quently predominate. 
(,EOLOGICAL OCCURRENCE OF THE AMBER 
The Simojovel Area is located in central Chiapas in 
the Central Mesa region and parts of the Tabasco Coastal 
Plain. ‘The amber is collected primarily from rocks ex- 
posed in landslides (Plate NN NVIII), although some 
outcrops of beds containing amber occur along river 
banks and in road cuts. 
Although geological investigations of the amber- 
bearing beds were begun in 1956, little detailed strati- 
graphic information has yet been published. Licari 
(1960), in a preliminary study of the region, described 
the largely Oligocene Simojovel Group as consisting of 
approximately 6550 feet of well-bedded marine calcare- 
ous sandstones and mudstones with some intercalated 
lignitic seams. It is underlain by Eocene sandstones, 
shales and conglomerates and overlain by Miocene sand- 
stones and shales. The upper portion of the Simojovel 
Group, including a distinctive limestone member, is 
characterized by the presence of the marine gastropod 
genus Orthaulax, indicative of late Oligocene to earliest 
Miocene age. Amber has been found in the ‘‘Orthaulax 
[ 293 ] 
