336 BULLETIN OF THE BUREAU OF FISHERIES. 
the port of Tumbes, well known as the landing place of Pizarro. If so, the first 
impression of Peru is that which may have been anticipated of a tropical lati- 
tude—a region of thick vegetation, chiefly mangrove trees in swamps intersected 
by narrow winding estuaries, and traversed by a permanent river of considerable 
volume. ‘The local conditions are similar to those that prevail in the neighbor- 
ing territory of Ecuador. Naturally in such a region there is an abundance of 
shellfish, including oysters and many species of clams and crabs. 
Typical, however, as this Tumbes region may seem for the latitude (31%°S.), 
and fitting perfectly to the region lying northward, the locality is entirely unique 
for the coast of Peru. About 20 miles beyond the territorial line the aspect of 
the shore presents the sharpest change. As the southern limit of the delta of 
the Guaya is passed, the green luxuriance disappears abruptly to give place to 
shores of barren and desolate appearance, and this new aspect continues prac- 
tically unchanged for the remaining 1,400 miles of the Peruvian coast, and 
onward, in fact, into the domain of Chile. (Fig. 1, pl. x1.) 
The type of coast characteristic of the country is, then, the reverse of what 
one might expect of a tropical region. With shores rainless and barren, a 
most significant feature is the practical absence of large rivers emptying into 
the sea or mingling with the ocean waters in coastal sounds or bays. The portion 
of the country west of the lofty western cordillera, the watershed of the conti- 
nent, isa steeply sloping desert interrupted by the narrow valleys of numerous 
little rivers formed from the melting snows of the Andes. In the cooler season 
(May to September) the scant waters of these precipitous streams are soon 
exhausted by natural evaporation or seepage, or spent in the irrigation ditches 
of the fertile valleys. On the other hand, although in the warm period of No- 
vember to March the melting snows swell the rivers into torrents, the coast at 
this time is enduring its driest season, and the soils and irrigated farms are mak- 
ing their greatest demands upon the rivers’ flow. Such portion, then, as may 
eventually reach the coast in any season can form but a small lagoon, and this 
may be quite separated from the ocean by a narrow levee of shingle, which the 
surf builds up against the river. The mouth of the Rimac offers a good illus- 
tration of this interesting type of river mouth, across which one may walk 
dry-shod. (Fig. 2, pl. xi.) Beneath one’s feet the lagoon empties gradually into 
the ocean through the loose formation of water-worn stones. Only in times of 
excessive flood is the levee actually broken through to form a visible mouth. 
It is unnecessary to point out the significance to the fisheries, or to the 
natural history of the coast, of this general absence of estuaries, sounds, or brack- 
ish bays, such as would offer a quiet breeding ground for some kinds of ocean 
fishes, or afford a favorable environment for oysters, clams, and other valued 
shellfish. 
