66 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Head in adult specimens about 4^ in body, not including caudal; in depth, 3J; base of 
dorsal half as long as the distance to the insertion of the fin and one-fourth the length of 
the body; the first rays of dorsal about midway between base of caudal and line between 
cheek and opercle, or half way between snout and extremity of caudal; the dorsal is low, 
the rays about as long as the interorbital space. Pectoral fins are broad and short, inserted 
about the axis of the body and reaching origin of the dorsal and almost to anal, which is 
nearly under the first rays of the dorsal. Anal fin short; the first two rays undeveloped, 
the fourth l)eing the longest; this equals distance from snout to opercle; when the fin is 
depressed the rays reach as far as the origin of the last rays of the dorsal. The measure- 
ments of six large specimens are as follows : 
Total 
length. 
Length 
to caiulal. 
Heat! . 
Depth. 
Eye. 
Dorsal. 
Anal. 
Lateral 
line. 
mm. 
myn. 
mm: 
mm. 
mm. 
88 
77 
19 
*23 
5 
13 
18 
29 
82 
71 
18 
19 
4-5 
11 
8 
36 
79 
69 
17 
»24 
■i + 
11 
8 
31 
79 
69 
17 
19 
i + 
13 
8 
31 
75 
65 
15 
18 
4— 
12 
8 
31 
64 
T6 
16 
18 
3-h 
12 
8 
31 
*Abflomeu distended with young, i The two undeveloped rays were not included. 
In some specimens corresponding to P. reticnlaius there are 14 or 15 dorsal rays; the 
color of the male specimens is practically the same as that of the females, excepti}ig that 
the spot on the a.ual is lacking; size much smaller, the largest male taken having a total 
length of only 464- mm. The pectorals reach to the middle of the ventrals and the ventrals 
beyond the .anal opening; the insertion of the anal is much further forward than in the 
females and is nearer the snout than the dorsirl, the long modified rays reaching as far toward 
the caudal as do the longest dorsal rays when depressed. 
Several specimens seem to correspond with P. rellculatus. These may be described in 
the following manner: Snout broad, spatulate, the lower jaw projecting. Eye equal to 
snout, 34 in head, 2 in interorbital si^ace. Anal process in male I 4 in head, ordinarily witli a 
slight curve at the tip. Caudal peduncle .short. Anal fin inserted in front of dorsal. Dor- 
sal long, its length 3 in body. Coloration as in Pseudoxipliophorus Mmaculahis, hut darker 
and more profusely dotted with brown. A larger black spot on upper half of root of caudal 
and a trace of another behind gill-opening. Occiput and snout dark brown. Scales on 
back and sides with a dark-brown crescent. These do not appear on scales of lower X)arts, 
as in P. himacnlatus. Dorsal fin with dark-brown cross streaks made of dark spots. Fins, 
scales, cheeks, and opercles profusely dotted with brown. Head, 34; depth, 4; D. 15; A. 8. 
Scales, 31-8. Length, 24 inches. It ismy opinion that these s^^ecimens represent individual 
variation only and that but one species of the genus Pseudoxiphophorus is known. The 
validity of Pseudoxiphophorus in distinction from Ganibusia is also brought in question, since 
the length of the dorsal is made the jirincipal basis of generic distinction, and this is quite 
variable in the specimens collected. 
I 
