216 Percesoces and Rhegnopteri 



known as "fishes of the King," Pescados del Rey, Pesce Rey, or 

 Peixe Re, wherever the Spanish or Portuguese languages are 

 spoken. The species are, in general, small and slender fishes 

 of dry and delicate flesh, feeding on small animals. The mouth 

 is small, with feeble teeth. There is no lateral line, the color 

 is translucent green, with usually a broad lateral band of silver. 

 Sometimes this is wanting, and sometimes it is replaced by 

 burnished black. Some of the species live in lakes or rivers, 

 others in bays or arms of the sea, but never at a distance from 

 the shore or in water of more than a few feet in depth. The 

 larger species are much valued as food, the smaller ones, equally 

 delicate, are fried in numbers as "whitebait," but the bones are 

 firmer and more troublesome than in the smelts and young 

 herring. The species of the genus Atherina, known as "friars," 

 or "brit," are chiefly European, although some occur in almost 

 all warm or temperate seas. These are small fishes, with the 

 mouth relatively large and oblique and the scales rather large 

 and firm. Atherina hepsetus and A. presbyter are common in 

 Europe, Atherina stipes in the West Indies, Atherina bleekeri 

 in Japan, and Atherina insularum and A. lacunosa in Polynesia. 

 The genus Chirostoma contains larger species, with project- 

 ing lower jaw, abounding in the lakes of Mexico. Chiro- 

 stoma humboldtianum is very abundant about Mexico City. 

 Like all the other species of this genus it is remarkably excellent 

 as food, the different species constituting the famous " Pescados 

 Blancos" of the great lakes of Chapala and Patzcuaro of the 

 western slope of Mexico. A very unusual circumstance is this: 

 that numerous very closely related species occupy the same 

 waters and are taken in the same nets. In zoology, generally, 

 it is an almost universal rule that very closely related species 

 occupy different geographical areas, their separation being 

 due to barriers which prevent interbreeding. But in the lake 

 of Chapala, near Guadalajara, Prof. John O. Snyder and the 

 present writer, and subsequently Dr. S. E. Meek, found ten 

 distinct species of Chirostoma, all living together, taken in the 

 same nets and scarcely distinguishable except on careful 

 examination. Most of these species are very abundant through- 

 out the lake, and all reach a length of twelve to fifteen inches. 

 These species are Chirostoma estor, Ch. lucius, Ch. sphyrana, 



