88 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



3 in base of anal fin; base of anal fin 3^ 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. 

 37. Rceboides Giinther. 



Rceboides Giinther, 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 i2-f 22 =34. 



83. Roeboides guatemalensis (Giinther). 



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

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

 4, 1869; Huamuchal. 



Rceboides 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, subconical; mouth large; 

 maxillary long and slender, its tips reaching vertical from posterior 

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

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

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

 reaching anal ; ventrals i 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. 



