148 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
caudal peduncle rather slender, not especially deep, the least depth being 2.5 in head; eye small; 
scales moderate, not closely imbricated, those before dorsal somewhat reduced in size; lateral line little 
decurved, not wholly complete, an occasional scale without any pore; tins all small; origin of dorsal 
much nearer base of caudal than eye, and behind insertion of ventrals, its rays about half length of 
head; anal short; pectoral very short, not nearly reaching ventrals, its length equal to height of dorsal 
fin; ventrals very short, not nearly reaching vent; caudal not deeply forked, the lobes about 1.5 in head. 
Color in alcohol, grayish-olivaceous on back and upper part of side, the scales profusely covered 
with small dark punctulations; under parts paler; a broad dark median line from occiput to origin of 
dorsal, just in front of which it ends in a black blotch; a broad dark plumbeous band from humeral 
region along side to base of caudal fin, this band anteriorly somewhat above the axis of the body but 
following the axis posteriorly; dorsal, caudal, and pectoral fins dusky, the ventrals and anal pale. 
This species seems most closely related to Notropis aztecus Woolman, from which it differs chiefly 
in the more slender caudal peduncle, the larger eye, less rounded snout, and the coloration. 
The numerous cotypes show no appreciable differences. 
The presence of fully developed eggs in one of the cotypes indicates that the spawning time of 
this species in Lake Lerma is in the late summer. 
12 . Notropis frig-idus (Girard). 
A single specimen, 2 inches long, from a pool near Lake Santa Maria, Chihuahua, seems to be this 
species, though too badly mutilated to enable us to identify it with certainty. The character of the 
teeth can not be made out and the scales are rubbed off so that they can not be accurately counted. 
Head 4; depth 4.25; eye 3.5; snout 4; D. 7; A. 9; scales 5-35-6, 15 before the dorsal. Body 
slender, compressed; head small; mouth small, oblique, the lower jaw slightly included; scales thin, 
deciduous; fins small; origin of dorsal slightly behind base of ventrals. Color, pale yellowish or 
straw-color, a few dark punctulations along median line of back. 
13 . Agosia chrysogaster Girard. 
One specimen, 3.25 inches long, of this interesting little minnow is in the collection made by 
Messrs. Townsend and Barber near the summit of the Sierra Madre, Chihuahua. 
14 . Symbranchus marmoratus Bloch. 
One specimen, 12 inches long, from Cozumel Island, and two smaller ones, each 10.5 inches long, 
from Mujeres Island. Those from Mujeres Island were obtained by Mr. Goldman from the soft, slimy 
mud of a swampy, fresh-water pond about 2 miles from the southern end ot the island. “This pond,” 
Mr. Goldman says, “is 4 or 5 acres in extent and occupies a depression about a quarter of a mile 
from the open sea and only about 250 yards from the head of a salt-water lagoon, from which it is 
completely cut off, however, by a ridge 30 or 40 feet in height. The water in the pond is so shallow 
that it is everywhere filled with tall, growing, aquatic vegetation. There is a ranch close by, and to 
obtain water the people have dug holes at one end of the pond and walled them up with rocks to 
prevent their immediately refilling with soft mud. As it is, they gradually fill and have to be 
periodically cleaned. The only times the people ever see these eels are when these holes are cleaned. 
I happened to be there one day hunting birds and getting fish from the salt-water lagoon, and the 
people told me about the eels. After some difficulty l managed to persuade two men to undertake the 
job of cleaning the holes at once. They were hard to persuade, for they claimed they were apt to get 
fever from working in and overturning the mud. Many bushels of it were taken out and the eels 
found in cavities between the rocks. The people believe that the eels serve to purify the water. They 
assured me that no other fresh- water pond existed on the island.” 
Body very slender and eel-shaped, compressed posteriorly, the deepest part through base of head; 
head conic; tail very short, less than one-fourth total length; eye small, close to the end of snout; 
mouth horizontal, large; distance from tip of snout to angle of mouth contained three times in distance 
from tip of snout to posterior gill-opening; lijrs thin but long and overhanging; snout rounded, very 
short, equal to interorbital space; teeth small, those on jaws in a single row, except in the front of upper 
jaw where the rows from the sides join, forming a small patch; teeth on the palatines larger, conic, and 
in a patch anteriorly where the two rows join, a single row being on each side; gill-opening narrow, 
the width of the opening equaling distance between eyes; distance from vent to tip of tail 4.1 times in 
entire length; no fins except dorsal and anal, the latter extending from vent, the former beginning 
slightly in advance of this, both meeting at end of the narrowly pointed tail. Color in alcohol, dark 
olivaceous or brown, mottled with darker brown; under part of head and neck lighter. 
