126 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Measurements of ten specimens of Tetragonopterus argentatus. 
Measurements. 
Locality : 
Rio Verde at Eascon 
Length, of body in millimeters 
55 
47 
44 
47 
43 
42 
40 
38 
37 
37 
Depth of body expressed in hundredths of length 
35 
35 
36 
34 
34 
33 
34 
34 
35 
34 
Depth of caudal peduncle 
12 
12 
12 
11 
12 
12 
12 
12 
12 
12 
Length of head 
29 
29 
29 
27* 
27 
29 
29 
28 
30 
30 
Distance from snout to occiput 
28 
28 
28 
27* 
27 
28 
28 
29 
30 
29 
Tip of lower jaw to occiput 
28 
28* 
29 
27* 
28 
29 
29 
29 
30 
30 
Width of interorbital space 
9 
10 
10 
10 
9 
10 
10 
9 
10 
10 
Length of snout 
8 
8 
8 
8 
8 
8 
8 
8 
8 
74 
Diameter of orbit 
10 
10 
10 
10 
9 
10 
10 
10 
11 
11 
Distance from snout to dorsal tin 
5G 
53 
54 
54 
52 
53 
55 
58 
54 
54 
Insertion of dorsal to adipose tin 
33 
30 
37 
36 
36* 
36 
37 
35 
38 
33 
Height of longest dorsal rays 
23 
22* 
23 b 
22 
22 
22 
22 
22 
24 
24 
Distance from snout to anal lin 
08 
09 
69 
64 
67 
69 
69 
69 
68 
68 
Height of longest anal rays 
15 
15 
16J 
10* 
16 
16 
15 
15 
16 
15 
Distance from anal to caudal fin 
15 
15 
1C 
15 
14 
16 
14 
15 
15 
14 
Length of caudal fin 
27 
26 
28 
28 
27 
29 
29 
28 
28 
25 
Length of pectoral fin 
21 
20 
21 
22 
21 
20 
19 
22 
19 
22 
Distance from snout to ventral fin 
51 
53 
54 
50 
50 
52 
51 
52 
48 
53 
Length of ventral fin 
15 
14 
13 
15 
15 
14 
13 
15 
15 
15 
Number of dorsal rays 
10 
9 
9 
9 
9 
9 
9 
9 
10 
9 
Number of anal rays 
21 
20 
20 
21 
20 
20 
20 
20 
20 
19 
Number of pectoral rays 
13 
12 
13 
12 
13 
12 
12 
12 
12 
12 
Number of scales in transverse series 
15 
15 
14 
13 
13 
14 
14 
14 
14 
13 
Number of scales in lateral line 
37 
33 
34 
31 
34 
31 
31 
34 
30 
34 
P CECIL IID-Sj. 
17 . Fundulus heteroclitus (Linnaeus). Lagoons near Tampico. 
18 . Fundulus robustus Bean. Mouth of Laguna de Chapala, Jalisco. 
19 . Characodon variatus Beau. Rio Verde, Aguas Calientes. 
The large males have no dark spots. The dark, lateral color-band is very marked. In life there 
was a terminal band of bright orange-yellow on the caudal, and also a washing of the same color on 
the lower parts of the body posterior to the ventrals. In the small males the lateral dark band is 
more or less broken up into spots. There are spots on other parts of the body, generally arranged in 
a row on the lower parts posterior to ventral fins; terminal caudal band usually absent. The large 
females are similar in color to the small males. The small females are more spotted. 
20 . Characodon encaustus Jordan & Snyder. New species. Fig. 7. 
Type No. 6163, L. S. Jr. Univ. Mus. Locality, Laguna de Chapala, near Ocotlan, Jalisco, Mexico. 
Collected by J. 0. Snyder, December 26, 1898. 
Head 3.80 in length ; depth 3.66; depth of caudal peduncle 8 ; eye 3 in head ; snout 4; interorbital 
space 3.5; height of dorsal 4.5 in length; anal 6.5; length of pectoral 5.33; ventral 6.5; caudal 4.33. 
D. 16. A. 16. Scales in lateral series 35; 
transverse series counting upward and 
forward from origin of anal 13 ; on caudal 
peduncle 9. 
Body deep, compressed; dorsal out- 
line almost straight from snout to origin 
of dorsal, concave from the latter point 
to base, of caudal ; ventral outline evenly 
curved from snout to posterior part of 
base of anal. Eye very large, located 
nearer to snout than to posterior edge of 
opercle a distance equal to longitudinal 
diameter of pupil. Mouth small, its width equal to two-thirds diameter of pupil ; maxillary protrac- 
tile; lower jaw projecting. Teeth in 2 series, outer series small, bicuspid, in single row, rather firmly 
attached; inner series minute, in small patches. Gill-openings restricted, not extending above base of 
pectoral. Gillrakers slender, equal in length to half the diameter of pupil. Alimentary canal short. 
Air-bladder large, extending posteriorly to a point above origin of anal. Dorsal fin inserted halfway 
between tip of snout and base of caudal; length of base a little less than height of fin ; anal inserted 
below middle of dorsal, its edge rounded; pectorals extending beyond bases of ventrals; ventrals 
extending to vent. Scales on body large ; upper posterior part of head and a narrow space below and 
posterior to eye with scales; other parts of head naked; small scales on basal part of caudal fin. A 
row of large pores above eye and at lower edge of suborbital patch of scales. No lateral line. 
Fig. 7 Characodon encaustus Jordan &, Snyder, new species. Type. 
