37§ CALIFORNIA ACADEMY OF SCIENCES. 6 



which it is named las Olas Altas. North of Puerto Viejo, 

 at a distance of about seven miles, are three large rocky 

 islands, very much alike, close together and in a right 

 line, known as the three Venados. Opposite them on the 

 shore is a similar headland, Camarron. About all these 

 headlands and islands are many rock -pools and basins 

 left filled with water by receding tides. Beyond the ex- 

 tremity of Vijia is a tall conical island, over 500 feet in 

 height, known as Creston. This is surmounted by a 

 lighthouse and is the most conspicuous land mark of the 

 harbor of Mazatlan. North of Creston lie a number of 

 large barren rocks of white volcanic rock, known col- 

 lectively as Islas Blancas. The scanty harbor of Mazat- 

 lan lies to the south of Vijia and Creston, between these 

 and the Isla de los Chivos and Isla de las Piedras. It 

 ends in a long deep winding channel, known as the Asti- 

 llero or Estuary, which extends around the south side of 

 the city, with many muddy arms lined with Mangrove 

 bushes, then turns to the south, forming for some ten 

 miles the narrow channel between Isla de las Piedras and 

 the mainland. No fresh waters of importance flow into 

 the Astillero and the tides form strong currents as the 

 waters pass in and out. 



At Altata, in the northern part of Sinaloa, is a small 

 harbor, the port of the capital City of Culiacan. 



Of the several rivers in the State, only one, Rio Presi- 

 dio or Rio de Mazatlan, was visited by us. This is a 

 swift clear stream, rising in the mountains. At Presidio 

 and Villa Union, where it was visited by us, it flows rap- 

 idly over gravel, being in January some three rods wide 

 and rarely more than two feet deep. 



The fishes of Sinaloa are known chiefly from the col- 

 lections made by Dr. Charles H. Gilbert in the winter of 

 1881. Under the auspices of the U. S. Fish Commission, 



