272 BULLETIN OF THE 
rounds it. The topography and geology of this locality alone is so inter. 
esting and complicated that it would require a lengthy paper to describe 
it, and it can best be explained in brief by reference to the accompanying 
topographic sketch and section. (Plate I. Fig. 4, Plate II. Fig. 9.) 
Two diminutive rivers flow into the harbor, the Yumuri of Matanzas 
and the San Juan, both emerging suddenly from the highland. The 
highland or sky line surrounding the harbor on the two sides is about 
one hundred meters (three hundred and fifty feet) in altitude, as deter- 
mined by aneroid at Mount Serat, and constitutes a flat-topped mesa or 
plateau north of the Yumuri, and a poorly defined bench against a still 
higher hilly region south and east of that river. Out of this plainly 
marked level are carved the sloping and narrow lowlands immediately 
surrounding the harbor, upon which the city is built. Between the 
level of the city and the highlands the narrow remnants of a few ter- 
races or pausation planes are faintly traceable. One of these is about 
one hundred and fifty feet above the sea, and the other, upon which is 
located the railway station back of the city, and which constitutes the 
bench back of the Versailles church north of the Yumuri River, is about 
fifty feet. 
The Yumuri enters the harbor valley through a deep precipitous 
cafion cut athwart the high level above described. Viewed from the 
city, this cafion appears to be a chasm in a mountainous background. 
Upon ascending it for halfa mile it is seen to open out into a wide and 
beautiful amphitheatre, some four leagues in circumference, bordered by 
steeply sloping walls, and with a wide sub-level bottom. The bottom 
of this valley is only a little above sea level, and if submerged a few 
feet would become a circular harbor from the inflow of the sea. 
Upon climbing to the summit of the cafion to the Church of the 
Hermit, upon the high level, a grand view of this peculiar amphitheatre 
is seen. It is clearly carved out of a vast sub-level plateau having the 
general altitude of the Mount Serat eminences, whose remnants consti- 
tute the plateau lying between the Yumuri River and the sea on the 
west side of the harbor to the north and east of the amphitheatre. 
Traces of this plateau? also surround the south margin of the amphi- 
theatre, forming a bench from which rises a line of higher hills, more 
serrated, —the same which are crossed and seen between Havana and 
Matanzas, and which do not exceed six hundred feet in altitude. This 
remarkable valley and the more remarkable caiion which connects it 
1 See A. Agassiz, Bull. Mus. Comp. Zool., Vol. XX VI. No. 1, Plate XLII. 
2 Tbid., Plate XLII. 
