Cope.] 688 [May 17, 
This species appears to be allied to the X. falcatus, from Guiana, as de- 
fined by Giinther, but this author does not allude to some of its prominent 
characters. According to his description, that is a stouter species having 
the depth one-fifth the length, and the head smaller, or one-fourth the same. 
It has also a humeral spot. AJIl my specimens have 25 anal rays, not 28-80 
as given by Dr. Giutber. 
66. XIPHORHAMPHUS FALCIROSTRIS Cuv., Giinther. 
This species, of which I have two specimens, differs from the last as fol- 
lows: Anal radii (soft) only 21; dorsal fin in the posterior third of the 
length minus caudal fin ; scales equal, 36—151-+8—15. Head and muzzle 
wider, the latter without ridges above, and with only one foramen for the 
inferior canines. First suborbital bone wider. It differs from Giinther’s 
description in having the muzzle considerably shorter than the distance 
from the anterior border of the orbit to the preopercular border. I add that 
the supraoccipital crest is short, and the epiotic region rugose. Depth one- 
sixth length without caudal fin; length of head in same 3.7 in the same. 
There is a caudal but no humeral spot. Total length M. .285. 
Coll. 1873-77. 
67. HypDROLYcUS PECTORALIS Ginther, Ann. Magaz. Nat. Hist., 1866. 
Coll. 1873-77. Nauta. 
68. RAPHIODON VULPINUS Spix., Agass. 
Coll. 1873-77. 
69. RAPHIODON GIBBUS Spix., A. 75. 
Coll. 1873. 
70. KipHOSTOMA 't=DO Cope, Proceed. Acad. Philada., 1872, p. 267, Pl. 
XIII, fig. 2. 
Specimens of this species in better preservation than the types, show that 
the belly is black, and that there is a large black spot on the inferior side 
of the caudal peduncle at the base of the caudai fin. They also show that 
all but the anterior portion of the lateral line is wanting. These characters 
indicate that this is a distinct species from the X. maculwtwm with which it 
is united by Steindachner. At least they are not found in author’s figures 
and descriptions of the latter. 
71. CHARACIDIUM STEINDACHNERI, sp. nov. 
This, the third species of the genus, is of more slender form than either 
of the two known hitherto, and has a smaller number of longitudinal rows 
of scales. The number of transverse rows is as in C. fasciatum the type, 
and larger than in C. etheostoma. The fin rays are less numerous than in 
C. fasciatum. 4 
Radii; D.9; A. 7; V. 9; the first ray a little behind the origin of the 
dorsal fin, and the produced apex of the fin nearly reaching the anal. The 
pectoral fin is also prolonged, attaining the base of the ventral. Thelength 
of the head is greater than the depth of the body entering the length less 
the caudal fin, 4.33 times. The greatest depth enters the same 6.5 times. 
Scales 4-837—2 or 1}; 54 rows on the stout caudal peduncle. Lateral line 
complete. 
