DESCRIPTION OF PANTOSTEUS SANTA-ANA, A NEW 
SPECIES OF FISH FROM THE SANTA ANA RIVER, 
CALIFORNIA. 
By JoHn OrrerBEIN SNYDER, 
Of Stanford University, California. 
A small collection of fishes taken from the Santa Ana River near 
Riverside, California, by Mr. Edmund Heller, in May, 1897, contains 
a Pantosteus which differs from any of the known forms. It is here 
described as Pantosteus santa-anwynew species. 
Pantosteus santa-anw 1s closely related to P. delphinus of the Colo- 
cado basin, a form with a thick skull and greatly restricted fonta- 
nelle, which early becomes obliterated. It differs from it in having 
larger scales. It seems to have no affinities with P. arizonew or P. 
clarkd, the other species indigenous to the Colorado basin. In exter- 
nal characters it resembles P. generosus of the Salt Lake basin. It 
has a much thicker skull, the fontanelle being closed, even in very 
small individuals, while in P. generosus it is evident in examples 
measuring 200 millimeters or more in length. It differs widely from 
the Pantosteus of the San Joaquin basin and also from the species of 
western Nevada and adjacent parts of California. 
PANTOSTEUS SANTA-ANZ, new species. 
Head 44 in length to base of caudal; depth 44; depth caudal pe- 
duncle 10; snout 1,% in head; eye 64; width interorbital space 2? 
D. 11; A. 7; scales in lateral series 79; before dorsal 32. 
Body robust, the head long; interorbital space convex. Skull very 
thick, the fontanelle completely closed even in individuals not more 
than 45 mm. long. Width of mouth contained 4 times in length of 
head; width, including lips, equal to length of snout; lips with nar- 
row, smooth shields within; papille irregularly arranged, about 6 
rows on upper lip, the inner ones large, the outer ones very small; 
lower lip not deeply cleft, there being 5 rows of papillae between 
cleft and inner margin. 
PROCEEDINGS U. S. NATIONAL MuSEuM, VOL. XXXIV—No. 1595. 
Proce. N. M. vol. xxxiv—08 3 33 
