280 BULLETIN OF THE 
River of Matanzas are certainly eroded in the manner Mr. Crosby alleges, 
not through coral reefs, but through older rocks which have been ele- 
vated across the tracks of the rivers, though most of the harbor necks 
in the east end of the island are certainly old submarine reef valleys, 
resulting merely from the fact that the coral has grown up around them. 
The harbor of Havana is a much better example of supposed subsidence 
than is that of Baracoa, but even here the channel cut out. of the old 
Tertiary walls of the harbor does not necessarily imply that the land was 
formerly higher than now, for the heavy surf may be seen cutting many 
similar indentations into the limestone sea front, which action, with the 
aid of that of the rivers, could have easily made these indentations. 
Concerning the mouths of the rivers themselves, their alluvial de- 
posits and the evidence of their valleys may be interpreted to mean 
elevation more positively than Mr. Crosby interprets them to mean sub- 
sidence, nor can I understand why he calls them “half drowned.” There 
is a singular absence of fiord-like valleys or indentations, or of ancient 
estuarine deposits, around the coast of Cuba, such as ordinarily indicate 
subsidence. (Plate I. Fig. 6.) In fact, the rivers in nearly all cases, 
like the Yumuri of the east, run directly to sea level through almost 
vertical chasms cut straight across the line of terraces, and are void of 
any terraces within their cafions, showing unmistakably that they have 
been cut down to sea level since the terraces and their own deltas were 
elevated, and that there is no superimposition indicative of subsidence 
previous to the reef-making epoch. 
That some of these rivers do at present reach tide level a short dis- 
tance from the beach is true, but so short is this distance that vessels 
can always obtain fresh water from them by sending light boats up 
stream less than a mile. I think that this slight indentation of tide 
level up these rivers is indicative, not of “drowning,” or of an ancient 
subsidence, but that, on the contrary, it means merely that the rivers 
and surf are doing their normal work of degrading the land, If they 
were really drowned rivers they would be navigable some distance inland, 
but in the three largest streams, the Armendaris of Havana and the two 
Yumuris of Matanzas and Baracoa, I found it impossible to go inland 
over a mile in the shallowest row boat, being soon retarded by rapids. 
On the other hand, these streams are new forming delta deposits in 
places outside their mouths, which is more indicative of present eleva- 
tion than of subsidence. Furthermore, at the mouth of the Yumuri of 
the east these deltas were also formed immediately preceding the eleva- 
tion of the coast reef, which may be accepted as evidence of elevation at 
