Jordan and Evermann. — Fishes of North America. 3175 
oi^ercle; mouth horizontal, lower jaw projecting; lips thick, the lower 
without freniam, folding over the upper at their union; premaxillary pro- 
tractile; maxillary small, nearly vertical in position, and almost hidden 
by tlie large preorbital; teeth on both jaws, in 2 series, the oirter a single 
row of 24 canines, largest in front, growing smaller posteriorly, the inner 
series villiform; all of the teeth with brown-colored tips; gill-membranes 
free from isthmus ; brauchiostegals 5 ; gill-rakers on first arch 9, short, 
blunt, far apart. Body covered with large scales; cheek, opercle, inter- 
opercle, subopercle, and occipital portion of head with small scales; 
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 
lino 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 
rather stiff distal, ray-like attachment, the anterior edge of which pro- 
jects above the membrane of fin; tips of fourth and fifth rays of dorsal 
uniting to form a thread-like filament about as long as the diameter of 
orbit; dorsal, when depressed, extending on caudal one-third its lengths 
first anal spine shortest, others growing gradually longer and heavieiy 
the last 2| times as long as the first; spines with distal attachments simi- 
lar to those of dorsal, third and fourth rays longest, united at their tips, 
forming a slender filament ; tip of anal extending a little farther posteri- 
orly than that of dorsal ; caudal rounded ; tip of pectoral rounded ; ven- 
trals located slightly posterior to base of pectoral, extending to vent, 
outer ray longest, ending in a filament. Color dark, an oblong brownish- 
black spot at base of each scale on side of body, the spots growing less 
distinct above the pectoral ; membranes of dorsal, anal, and caudal with 
small spots, these more distinct and regularly arranged on soft parts of 
dorsal and anal; pectoral and ventrals without spots. 
Young individuals have a brownish-black spot at base of catidal and on 
side of body at tip of pectoral; a less distinct spot at upper edge,of gill- 
opening and also below posterior end of base of dorsal. The darker of 
these spots are sometimes faintly indicated on the larger individuals. 
Morelos, Mexico. (.Jordan A: Snyder.) 
Known only from Eio Ixtla at Puente de Ixtla, Morelos, Mexico. (Type, 
Xo. 6150, L. S. Jr. Univ. Mus. Coll. .Jordan & Snyder.) 
Heros istlanvs, Jordan & Snyder, Bull. U. S. Fish Coni. 1899 (1900), 144, Rio Ixtla, 
Morelos, Mexico. 
Page 1542. After Xeetroplus nicaragnensls, Gill A: Bransford, insert: 
19.51 (a). XEETHOPbl'.S CAKPIXTIS, Jordan A: Snyder. 
Head 2^ ; depth 2; depth of caudal peduncle 6; eye 5 in head; snout 2i ; 
interorbital space 2|; longest dorsal spine 24; ray Ijr; longest anal spine 
2, ray 1^; length of pectoral 1^ ; ventrals 14; caudal 1^; D. XVI, 10; A. 
V, 8; P.15; scales 26-17,7 on caudal peduncle. Body compressed, deep- 
est part above ventrals ; dorsal outline straight from tip of snout to a 
