138 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
except occasional natural surface tanks in which some water is found. The entire 
country is, however, underlaid by water approximately at sea level. At various 
places over the country are natural wells, called “cenotes.” These are natural 
excavations in the limestone rock, usually with more or less water at the bottom. 
The distance from the surface of the country down to that of the water in the cenotes 
seems to vary with the elevation of the country above sea level. Near the seashore, 
where the elevation of the country is but a few feet above the sea, the water in the 
cenotes will be only a few feet beneath the land surface. The elevation of the coun- 
try increases toward the interior and the depth at which the water stands in the 
cenotes becomes correspondingly greater. These wells are usually approximately 
circular and vary from a few feet to 50 to 75 yards in diameter. The walls are more 
or less perpendicular, and it is difficult to reach the water; however, it is usually 
possible to find irregularities or steps in the wall, on at least one side, by means of 
which the water may be reached. Frequently the wells are wholly inaccessible. 
Sometimes the well is in a sink or cave. 
In some wells the water is quite shallow, while in others it is of unknown depth. 
The water usually appears green, as in all limestone regions, but in some shallow 
wells it seems to be somewhat muddy. There is usually a thin coating of fine dust on 
the surface of the water which becomes readily noticeable on throwing any object into 
it. The water is said to be pure and sweet, but strongly charged with lime. There 
is a belief prevalent among the natives that these wells are connected. However 
this may be, the presence of fish in them is a most interesting fact for which it is 
not easy to account. How old the cenotes are can, of course, be known only approxi- 
mately, but they have certainly been in existence a long time. 
The well at Chichen Itza from which fishes were obtained is nearly circular, 
probably 60 yards across, and very deep, the water surface being about 90 feet below 
the land surface. Mr. Goldman states that he has seen fishes in several different 
wells on the east coast near Puerto Morelos, and that the natives say there are fish 
in all the larger ones. The only species thus far obtained from these wells is ITeros 
urophthcdmus , 7 specimens of which were obtained by Mr. Nelson from the Chichen 
Itza cenote. Mr. Goldman thinks the fish he saw were of this species. Mr. Nelson 
heard that cat-fish occur in a well at Chichen Itza, but did not see any specimens. 
According to the natives the fish in these cenotes disappear at intervals and return 
again. At certain times they can neither be seen nor caught; at other times they may 
not only be caught, but are seen swimming about at the surface. 
At the time of Mr. Nelson’s visit, which was during the second week in I ebruary, 
none could be caught, and the natives said they were away. The seven specimens 
obtained had been secured previously, perhaps a year or two before, and kept in a 
large masonry water-tank which was supplied with water by a wind pump. They 
had been caught by means of hook and line baited with pieces of meat. They had 
apparently bred in the tank, as many very young ones were seen swimming about. 
Another lot of fishes, chiefly salt-water species, was obtained at Progreso, which 
is on the north coast of Yucatan, only a few miles from Merida, the principal town. 
Some were obtained from fishermen, while others, chiefly Cy prinodonts, were seined 
in a small lagoon; others were gotten at Puerto Morelos, situated on the east coast of 
Yucatan. Some five or six species were obtained here from the sea, and a lot of the 
smaller species from a small lagoon. 
