132 Field Museum or Natural History — Zoology, Vol. X. 



This species inhabits fresh-water streams of* the Pacific Slope from 

 Sinaloa, Mexico, to Ecuador. 



Turrubales (i), 115 mm.; Orotina (28), 73 to 220 mm.; Jesus Maria 

 (7), 115 to 120 mm.; Rio Machuca (i), 200 mm. (Ah'aro). 



Sicydium pittieri Regan. 



Sicydium pittieri Regan, Ann. & Mag. Nat. Hist., 1907, 260 (Rio 

 Grande de Terraba, Costa Rica); — Regan, Biol. Cent. Amer., 

 1908, 185. 



Turrubales (i), 62 mm. 



Sicydium. altum Meek. 



Sicydium altum Meek, Pub. Field Mus., Zool. Scr., vii, 1907, 149 

 (Turrialba, Costa Rica); — Regan, Biol. Cent. Amer., 1908, 185. 



Males with the high dorsal fins, the longest spines 3 in body. The 

 head of this species is broader and interorbital wider than the preceding. 

 Young individuals (40 mm.) have 7 broad vertical bars on the side, 

 becoming faint on larger (80 mm.) specimens, and three narrow ones 

 on caudal fin. This species is very abundant on the gravelly bottom 

 and on the rocks in clear running water. They rest attached to rocks 

 by the suctorial disk on the pectoral fins. 



La Victoria (22), 36 to 84 mm.; Parismina (i), 50 mm.; Zent, April 

 15 (io)> 37 to 80 mm.; Zent, April 12 (5), 53 to 65 mm.; El Guayabo 

 (2), 85 to 98 mm. (Alfaro). 



Family Gobiesocidae. 



Gobiesox costaricensis Meek. 



Gobiesox costaricensis Meek, Pub. Field Mus., Zool. Ser., x, 191 2, 

 74 (Zent, Costa Rica). 



These small fishes can be seen clinging to rocks in clear water in 

 considerable numbers, but their capture is very difficult. This species 

 is probably a resident of fresh water only. 



Zent, April 12 (3), 50 to 61 mm.; Parismina (i), 41 mm.; Turrubales 

 (2), 42 mm. 



