272 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 95. 
Genus LAEMOLYTA Cope 
Laemolyta Corn, Proc. Acad. Nat. Sci. Philadelphia, vol. 23, p. 258, 1872 (type, 
Schizodon taeniatus Kner).—EIGENMANN and ALLEN, Fishes of western 
South America, p. 302, 1942 (Orinoco). 
Schizodontopsis Garman, Bull. Essex Inst., vol. 22, No. 4, p. 18, 1890. (Type, 
Schizodon taeniatus Kner.) 
LAEMOLYTA ORINOCENSIS (Steindachner) 
Anostomus orinocensis STEINDACHNER, Denkschr. Akad. Wiss. Wien, vol. 41, p. 
154, pl. 2, fig. 7, 7a, 1879 (Ciudad Bolivar, Venezuela); Anz. Akad. Wiss. 
Wien, vol. 16, p. 150, 1879.— Garman, Bull. Essex Inst., vol. 22, No. 4, p. 20, 
1890. 
Laemolyta orinocensis E1IGENMANN and E1GENMANN, Proc. U.S. Nat. Mus., vol. 
14, p. 50, 1891 (Orinoco). 
Genus HYDROLYCUS Miller and Troschel 
Hydrolycus MtiuER and TroscHeEu, Arch. Naturg., vol. 10, No. 1, p. 98, 1844; 
Horae ichthyologicae, pt. 1, p. 19, pl. 5, fig. 2, 1848. (Type, Hydrocyon 
scomberoides Cuvier.) 
KEY TO THE SPECIES OF HYDROLYCUS 3 
la. Pelvic fin base remote from midline of belly, distance from upper edge of 
pelvic base to midventral knifelike edge of belly about equal to least 
depth of caudal peduncle; anal rays 43 to 48 (probably iii, 40 to iii, 45); 
pectoral almost always i, 17; pelvic i, 8; a black spot at base of lower and 
upper pectoral fin rays, another on adipose fin; humeral black blotch 
roundish; distal portion of caudal fin rays pale. 
Hydrolycus pectoralis (Giinther) 4 
1b. Pelvic fin base little above midline of belly, distance from upper edge of pelvic 
base to midventral ridge (not a thin keel) 2 to 2% times in least depth of 
caudal peduncle; anal rays 33 to 35 (probably iii, 31 to iii, 33); pectoral 
almost always i, 16; pelvic i, 8; no black spot at base of lower pectoral fin 
rays and no black blotch on inside of base of upper pectoral fin ray; 
adipose fin with black spot; humeral black blotch elongate; distal half of 
caudal fin rays blackish, contrasting with pale basally. 
Hydrolycus scomberoides (Cuvier) 
HYDROLYCUS SCOMBEROIDES (Cuvier) 
PAayYARA 
Hydrocyon scomberoides Cuvier, Mem. Mus. Hist. Nat. Paris, vol. 5, p. 357, pl. 27, 
fig. 2, 1819. : 
Cynodon scombroides PrrErs, Monatsb. Akad. Wiss. Berlin, 1877, p. 472 
(Venezuela).—R6u1, Fauna descriptiva de Venezuela, p. 385, 1942 (Venezuela) 
13 Since no specimen of the third species, Hydrolycus copei Gill, is available for examination, I am unable 
to place it correctly in the above key. I quote Gill’s description from Proc. Acad. Nat. Sci. Philadelphia, 
vol, 22, p. 98, 1870: 
“DPD. 11. A. 43. The height enters 234 times in the length (exclusive of the caudal), the length of the head 
314; the profile between the nape and convex snout is moderately incurved; the interorbital space is slightly 
arched, and about equal to the orbit, the snout, and a quarter of the head’s length. The maxillary passes 
considerably behind the vertical of the posterior border of the orbit. The dorsal fin commences above the 
anus. The pectorals pass for a third of their own length beyond the tip of the ventrals, and the ventrals ex- 
tend backwards to the third or fourth anal ray. 
“The lateral spot is faint, and above the lateral line, just in advance of the vertical of the anus.’’ From the 
Napo and Maranon Rivers. Known only from the four types. 
14 Based on Giinther’s original description and three specimens in the United States National Museum, 
Nos. 5686, 39402, and 94669. Not yet reported from Venezuela. 
