JULY, 1907. FISHES OF GREAT LAKES, NICARAGUA MEEK. in 



Genus Koeboides Gxinther. 

 But one species of this genus is known to occur in Central America, 



Roeboides guatemalensis Giinther. 



Head 3.9; depth 2.9 to 3 ; D. 10; A. 48; scales 18-80-19. Body 

 elognate, much compressed; profile S-shaped; head small; mouth 

 large, oblique; maxillary reaching vertical from middle of eye, its 

 length 2 in head; upper jaw the longer;, mandible strong, its length 

 1.9 in head; diameter of eye 2.9 to 3.2; interorbital width 2.9 to 3.2 

 in head; jaws subequal; gill rakers slender, 7+9; origin of dorsal 

 behind that of anal, its distance from end of snout 1.8 to 1.9 in length 

 of body; length of dorsal 2 in head, its height equaling head; anal 

 fin very long, its base 1.9 in body; origin of anal to tip of snout 

 2.3 to 2.4 in body; pectorals 1.2 in head; ventrals 1.3; lateral line 

 straight, complete. 



Color olivaceous, a darkish band made up of small dark spots 

 above lateral line ; a faint humeral blotch ; membrane of anal fin with 

 many small dots, other fins usually plain, occasionally a black spot 

 just below lateral line and above middle of pectoral fin. A single 

 specimen of this species from San Geronimo, Oaxaca, Mexico, has the 

 upper jaw decidedly longer than the lower; in all other respects like 

 specimens from San Francisco, Nicaragua. 



This species occurs in the waters of the Pacific Slope from San 

 Geronimo, Oaxaca, in Mexico to Lake Nicaragua, and in the Rio 

 Chagres. It was not taken by Miller in the Rio Montagua, and is not 

 known from any Atlantic Coast stream north of the lakes in Nicaragua. 



San Francisco (17), 65 to 125 mm.; Jenicero (i), 85 mm. 



Family Elopidse. 



The presence of a gular plate between the branches of the lower 

 jaw at once distinguishes this family from all others represented in 

 the lakes. 



Tarpon atlanticus? (Cuvier & Valenciennes) . SABALO. 



Megalops , Gill & Bransford, Proc. Acad. Nat. Sci., Phila., 



1877, X 87, Toro Rapids, Rio San Juan. 



Head 4; depth 3.8; D. 12; A. 20; scales 42. Body compressed, 

 little elevated; dorsal filament longer than head; mouth large, armed 

 with pointed teeth. 



