Marcu, 1914. List or Fisues or Costa Rica — MEEK. 107 
85 to 130 mm. (Alfaro); Paso Agres (1), 100 mm. (Alfaro); Turrubales 
(5), 75 to 115 mm. (Alfaro); Rio Higuerén (48), 45 to 103 mm. (Alfaro) ; 
Las Cafias, Taboga (50), 30 to 40 mm. (Alfaro). 
Astyanax regani Meek. 
Astyanax regani Meek, Pub. Field Mus., Zodl. Ser., vit, 1908, 207 
(Las Cafias, Costa Rica, Pacific Slope). 
This species is nearest to A. albeolus. It differs in being more 
slender and more robust anteriorly. The snout is blunter and more 
decurved, the fins slightly shorter. In this species the anterior dorsal 
rays are shorter than the head, in A. albeolus they are as long as, or , 
even longer than, the head. A. regant also has a shorter anal base. 
Las Cafias, Costa Rica (type), 135 mm. (Alfaro); Pacific Side, 
Costa Rica (1), 100 mm, (Alfaro); Turrticares (3), 95 to 110 mm. 
(Alfaro). 
Bryconamericus scleroparius (Regan). 
Tetragonopterus scleroparius Regan, Ann. & Mag. Nat. Hist., 1908, 
455 (Rio Iroquois). 
Bryconamericus peruanus rice Eigenmann, Bull. Mus. Comp. Zoél., 
1908, 106 (Chitaria, Costa Rica). 
Astyanax robustus Meek, Pub. Field Mus., Zodl. Ser., x, 1912, 69 
(Virginia River, Costa Rica). 
This species varies considerably. The young, usually the smaller 
specimens up to 70 mm., have a higher and more pointed dorsal, the 
free edge of the fin being straight or slightly convex. The caudal lobes 
are pointed, and the color silvery (B. scleroparius (Regan) and B. p. 
rice Eigenmann). The larger specimens (140 mm.) have a much more 
robust body, the caudal peduncle being very broad; the dorsal fin is 
shorter, and the free edge convex. The caudal lobes are very short 
and rounded. The color of the large specimens is very dark, with a 
reddish tinge in life (Astyanax robustus Meek). The faint humeral 
spot on the young apparently disappears with age. Caudal spot 
scarcely defined in the large specimens, but present in the smaller ones, 
extending on the rays to the end of the caudal fin. Inner premaxillary 
teeth 4-4, the outer 5-—s. 
La Junta (5), 76 to 100 mm.; Virginia (50), 75 to 143 mm.; Parismina 
(30), 80 to 130 mm.; Zent, April 12 (8), 85 to 115 mm.; La Victoria (6) 
95 to 120 mm.; Guapilis (27), 85 to 122 mm.; Chitaria (3), 82 to 95 mm. 
(Alfaro). 
