144 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Total length of type 61 millimeters. Younger examples, measuring about 43 millimeters, have 
the body a little deeper and the head shorter. The vertical color hands on posterior half of body are 
more distinct on the younger specimens. 
Measurements of ten specimens of Cichlasoma steindachneri. 
Measurements. 
Locality: Bio Verde near Rascon, San Luis Potosi, Mexico. 
Length of body in millimeters 
48 
36 
34 
34 
32 
31 
31 
32 
30 
30 
Depth of body expressed in hun- 
dredths of length 
35 
38 
40 
37 
36 
39 
38 
40 
38 
38 
Depth of caudal peduncle 
14 
15 
15 
15 
15 
15 
15 
15 
15 
15 
Length of head 
40 
37 
38 
39 
35 
37 
38 
40 
37 
36 
Width of interorbital space 
8 
9 
9 
9 
9 
10 
9 
9 
8 
9 
Length of snout 
15 
13 
14 
13 
12 
13 
13 
13 
12 
12 
I >iameter of orbit 
12 
12 
13 
12 
12 
12 
12 
13 
12 
12 
Distance from snout to dorsal fin 
47 
45 
47 
45 
43 
45 
45 
46 
45 
46 
Height of longest dorsal spine 
12 
13 
14 
16 
14 
13 
14 
14 
15 
14 
Height of longest dorsal ray 
20 
20 
20 
21 
19 
19 
20 
18 
18 
19 
Distance from snout to anal fin 
72 
68 
67 
68 
69 
70 
69 
69 
66 
68 
Height of longest anal spine 
16 
13 
15 
15 
14 
15 
14 
16 
15 
15 
Height of longest anal ray 
19 
20 
20 
20 
17 
19 
28 
22 
20 
19 
Distance from anal to caudal fin 
14 
15 
15 
15 
16 
17 
16 
18 
15 
17 
Length of caudal tin 
28 
28 
30 
28 
26 
25 
27 
30 
25 
25 
Length of pectoral tin 
26 
29 
28 
26 
26 
27 
27 
31 
26 
25 
Distance from snout to ventral fin . . . 
46 
45 
43 
46 
44 
43 
44 
44 
43 
41 
Length of ventral fin 
23 
25 
24 
23 
20 
23 
23 
24 
23 
22 
Number of dorsal spines 
16 
16 
16 
16 
16 
16 
15 
16 
16 
16 
Number of dorsal ravs 
10 
10 
10 
10 
9 
9 
11 
10 
10 
10 
Number of anal spines 
5 
5 
5 
5 
5 
5 
5 
5 
5 
5 
Number of anal rays 
8 
8 
8 
8 
7 
8 
8 
8 
8 
8 
Number of scales in lateral line 
26 
28 
25 
27 
27 
27 
26 
27 
26 
29 
Number of scales in transverse series . 
14 
14 
13 
14 
15 
15 
14 
15 
14 
14 
38 . Heros cyanoguttatus (Baird & Girard). 
Some fishes from lagoons near Tampico we identify as Heros cyanoguttatus. They agree closely 
with descriptions of that species, hut have a decidedly longer and sharper snout than has the specimen 
figured by Girard. (Girard, U. S. and Mex. Bound. Sur., Ichthyology, 30, pi. 4, figs. 9-12. ) 
39. Heros istlanus Jordan & Snyder, new species. Mojarra. Fig. 21. 
Type No. 6150, L. S. Jr. Univ. Mus. Collected by Jordan & Snyder January 3, 1899, from Rio Ixtla 
at Puente de Ixtla, Morelos, Mexico. 
Head 2.80 in length; depth 2.66; depth of caudal peduncle 7 ; eye 4.50 in head; snout 2.25; inter- 
orbital space 3.50; longest dorsal spine 2.80; ray (without filament) 1.40; longest anal spine 2.60; 
ray (without filament) 1.33; length of pectorals 1.50; ventrals 1.33; caudal 1.20; D. xvi, 10. A. v, 8. 
P.14. Scales in lateral line 28; in transverse series 18. 
Body elongate, compressed, deepest part above insertion of ventrals ; dorsal outline rising rapidly 
to origin of dorsal, interrupted by a shallow notch above eye falling gradually to base of last spine, 
from which point the descent to the caudal peduncle is more abrupt; ventral outline evenly rounded. 
Interorbital space convex; eye large; orbit circular, equally distant from tip of snout and posterior 
edge of opercle; mouth horizontal, lower jaw projecting, lips thick, the lower without frenum, 
folding over the upper at their union; premaxillary protractile; maxillary small, nearly vertical in 
position, and almost hidden by the large preorbital. Teeth on both jaws in two series, the outer a 
single row of 24 canines; largest in front, growing smaller posteriorly; the inner series villiform; all 
of teeth with brown-colored tips. Gill-membranes free from isthmus. Branchiostegals 5. Gillrakers 
on first arch 9, short, blunt, far apart. 
Body covered with large scales, the cheeks, opercles, subopercles, and occipital portion of the 
head with small scales; the ventral part of head, preorbital area, snout, and anterior part of inter- 
orbital space naked; one row of scales extending on bases of dorsal and anal fins; scales of body 
weakly ctenoid ; scales of head smooth ; lateral line interrupted on the nineteenth transverse row of 
scales, beginning again 3 scales lower down, and 2 scales in advance of where it left off and extending 
to base of caudal. First dorsal spine short and slender, others gradually longer and heavier; posterior 
spine longest; each spine with a distal extension of stiff membrane; tip of fourth ray of dorsal extend- 
ing as a thread-like filament about as long as the diameter of orbit; dorsal, when depressed, extending 
on caudal onc-third its length; first anal spine shortest ; others growing gradually longer and heavier; 
the last 21,- times as long as first; spines with distal attachments similar to those of dorsal; third and 
