88 Field Columbian Museum — Zoology, Vol. V. 



3 in base of anal fin; base of anal fin 3 l < in body; anal fin falcate, its 

 longest rays equaling the length of the head; the lateral line incom- 

 plete, on 4 to 10 anterior scales; caudal fin widely forked. 



Color light olivaceous, body and fins sprinkled with black dots, 

 being more numerous on dorsal region and region near anal fin ; basal 

 half of anterior dorsal rays black; anal fin with many dark dots. The 

 largest specimen obtained is 1.75 inches in length. 



Subfamily Characinse. 

 )>7. Roeboides Gunther. 



Roeboides Gunther, Cat., v, 347, 1864. (Type, Epicyrtus microlepis 

 Rheinhardt.) 



Body oblong, rather elevated, covered with small scales; belly 

 rounded in front of ventrals ; pectoral and ventral fins near each other ; 

 humerus dilated or produced into a process before pectoral fin ; mouth 

 wide, with conical teeth in the premaxillary, maxillary, and mandible; 

 those on the mandible uniserial, on the upper jaw uniserial or biserial; 

 front of jaws with short, conical, tooth-like processes directed forward; 

 no teeth on palate; nostrils close together, separated by a membrane 

 only; gill openings wide, the membranes separate and free from the 

 isthmus; gill rakers slender, lanceolate; adipose fin present; verte- 

 brae 12 + 22 =34. 



83. Roeboides guatemalensis (Gunther). 



Anacyrtus guatemalensis Gunther, Cat., v, 347, 1864; Rio Chagres; 

 Huamuchal: Gunther, Fishes Cent. Amer., 479, pi. 82, fig. 

 4, 1869; Huamuchal. 



Roeboides guatemalensis Jordan & Evermann, Bull. 47, U. S. Nat. 

 Mus., 1896, 338. 



Rivers of the Pacific slope of the Isthmus of Tehuantepec and Cen- 

 tral America. (San Geronimo.) 



Head 3^; depth 3; D. 9; A. 50; scales 86. Body elongate, profile 

 rather gibbous at the nape; head small, subcorneal; mouth large; 

 maxillary long and slender, its tips reaching vertical from posterior 

 margin of the pupil, its length 2\ in head; snout equaling diameter of 

 eye, 3^3 in head; origin of dorsal fin slightly nearer tip of snout than 

 base of caudal fin; ventrals long and slender, i-i in head, their tips 

 reaching anal ; ventrals 1 y$ in head ; caudal fin deeply forked ; lateral 

 line straight, complete. 



Color olivaceous; sides with a silvery band; a faint dark blotch 

 above lateral line over middle of pectoral; a larger blotch below lateral 

 line above origin of anal; a faint caudal blotch; no markings on the 

 fins. Length about 3 inches. 



One specimen 3 inches in length was taken by me at San Geronimo. 



