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 tlie accompanying 

 topographic sketch and section. (Plate I. Fig. 4, Plate 11. 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 I'umuri River, is about 

 fifty feet. 



The Yumuri enters the harbor valley through a deep precipitous 

 canon cut athwart the high level above described. Viewed from the 

 city, this cafiou appears to be a chasm in a mountainous background.^ 

 Upon ascending it for half a 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 canon to the Church of the 

 Hermit, upon the high level, a grand view of tliis 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 raai-gin of the amphi- 

 theatre, forming a bench from which I'ises 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 canon which connects it 



1 Soc A. Agassiz, Rail. Mus. Comp. Zool., Vol. XXVI. No. 1, Plate XLII. 



2 Ibid., Plate XLIII. 



