528 WILBUR G. FOYE 
associated with diorites. The schist is composed of paper-thin layers 
of biotite bending around augen crystals of oligoclase and is similar 
to the schist occurring west of Micos Lagoon, near Tela, save that 
the mica is predominatingly biotite instead of muscovite. The 
microscope reveals a granular paste of fine quartz with rosettes of 
muscovite and parallel plates of chestnut-brown biotite. The 
diorite is a medium- to coarse-grained variety whose relation to 
the schist is unknown. Occasionally the diorite is sheared and 
epidotized. 
Rocks from La Ceiba and vicinity.—Among the streams extend- 
ing from the coast into the hills southeast of La Ceiba, the nearest 
is Rio Danto. A number of river pebbles were collected from its 
bed and one specimen was collected from an outcrop in the stream. 
The pebbles came from the higher interior hills near the headwaters 
of the coastal streams and were largely tonalites or allied types. 
The residual bowlders show that the region about La Ceiba is 
underlain by agglomerates and flows of acid rocks which toward 
the east around Tela are transformed into gneisses and schists 
by dynamic metamorphism. A tuffaceous agglomerate containing 
pebbles of felsodacite is much epidotized, but the microscope shows 
phenocrysts of oligoclase-albite replaced in part by a mosaic 
groundmass of small quartz particles. A trachyandesite from the 
same locality, outcropping in the river, is light yellow to buff in 
color and shows a slight flow structure. The thin section shows 
phenocrysts of oligoclase-albite which are not distinct in the hand 
specimen. ‘The groundmass is composed of a fine mosaic of feldspar 
and quartz and occasionally there are nests of feldspar in trachytic 
arrangement. 
From the hills north of Rubber Grove, a station on Vaccaro 
Brothers Railroad, 5 miles southeast of La Ceiba, aporhyolites 
and rhyolitic agglomerates were obtained. ‘The agglomerates are 
composed of red pebbles of aporhyolite and jasper bound together 
by a red quartzose cement. 
The Congrejal River flows into the ocean past the town of 
La Ceiba. Along its lower course acid flow rocks are exposed, but 
farther south among the mountains it cuts tonalites and gran- 
