SOME FOSSIL FISH SCALES FROM PERU. 



By T. D. A. Cockerell, 



Of the University of Colorado, Boulder. 



Some time ago Messrs. K. C. Heald and K. F. Mather collected 

 some fossil fish scales at Huacho, Peru. The locality is on the 

 coast, about 70 miles north of Callao. As it was desirable to deter- 

 mine the age of the rocks if possible, Dr. T. W. Stanton forwarded 

 the material to me for identification. 



The scales are well preserved and apparently represent a single 

 species belonging to the family Characidae (or Characinidae) . They 

 do not agree with any modern genus known to me but are related in 

 a general way to several. The deposit is doubtless fresh water and 

 of Tertiary age, but beyond this it is unsafe to make any positive 

 statement. The general similarity of the scales to those of modern 

 genera and the high degree of specialization of structure would suggest 

 rather late Tertiary, possibly Miocene. Berry * has described a series 

 of Miocene plants from northern Peru. 



CHARACILEPIS, new genus. 



Scales small, subquadrate to transversely elongate; apical field 

 broadly sculptureless, without radii, circuli, or etenoid structures; 

 basal field with broadly spaced transverse or arched circuli (some- 

 times angulate in middle), but no radii; between the basal and apical 

 fields a variable area (sometimes only narrowly developed, and at 

 sides) of transverse circuli set very close together, and quite inde- 

 pendent of the other series. Lateral line very distinct. 



Type of the genus. — CJiaracilepis tripartitus, new species. 



CHARACILEPIS TRIPARTITUS, new species. 



Scales, 3 to 4 mm. broad, polished. 



Huacho, Peru. 



A lateral line scale (fig. 1) may be considered the type. The scale 

 shown in figure 2 illustrates the sharp limitation of the sculptured 

 area, as in the modern Bryconamericus. In the marine genus Hypo- 

 rhamphus (fig. 7) there are two sets of circuli, broadly and narrowly 

 spaced, but one series is directly continuous into the other, as the 



1 Proc. U. S. Nat. Mus., vol. 55. 1919, p. 279. 



— — . 



Proceedings U. S. National Museum, Vol. 59-No. 2355. 



19 



