■ 893.] 51 
[Crawford. 
leagues east of this island. It was never a volcano, altliougli 
situated oul}' four or Hve miles south of that subteri-anean fissure 
exteiuliug- through western Nicaragua (over which all post- 
Mesozoie volcanic cones in Nicaragua are found) which prohably 
once connected the extensive group of active volcanoes in Costa 
Rica with the similar group in Salvador ; it has no volcanic 
crater nor vent, nor evidence that rock materials were extruded 
from it in a plastic condition (no trachyte, andesite, rhyolite, 
plionolite, or basalt) excepting fragments ejected from the vol- 
cano Momotombo that fell on it ; when viewed, however, from a 
short distance it has the appearance of a volcano, and it is usually 
so designated by tourists. 
A synclinal valley, the eastern part of which rises about 200 feet 
above the water in the lake, is on the western side of the island 
mountain Momotombito. This valley gradually wi<lens, for a 
distance of about 4,000 feet, to the lake ; the southern part of the 
syncline was filled during the Champlaiu epoch to above the gen- 
eral level on that side of the island by drift, volcanic ejecta, and 
debris deposited during a subsidence of the island ; it is now 
hardened into a partly stratified mass of conglomerate. The 
iiorthern and larger part of this syncline is "The Valley of Momo- 
tombito" in which were found the half-metamorphosed rocks 
sculptured with implements of flint or stone by artists living at an 
early date in the Neolithic age, together with numerous frag- 
ments of rough pottery made and used by the sculptors, small 
fragments of Hint, felsite, and jas]»er, not natural to the island, 
but brought there by the workmen, broken and used by them, 
and found cemented with de|)Osits of drift between some of the 
ro<-,ks. 
Description of the loorlis. Six stones that had been sculjitured 
into portraitures of men were found in the valley of Momotom- 
bito ; each stone was about 9 feet long, of which about 3 feet 
were set firmly in the rock floor of the valley, facing westward ; 
they were arranged about 500 feet from each other in two lines 
about 200 feet apart, beginning about 500 feet from the margin of 
the lake and extending eastward up the incline of the valley to 
within aljout 200 feet of the western ends of the north and south 
side of the foundation walls of the temple or observatory in course 
of construction; and this structure — or its foundation — was 
about 300 feet long; — east and west — and about 200 feet wide 
