Oct., 1907. Fresh-water Fishes — Meek. 135 



Tetragonoptenis csneus Gtinther, Proc. Zool. Soc. Lond., i860, 319, 

 Oaxaca, Mexico: Giinther, Cat., v, 326, Oaxaca, Mexico: 

 Meek, Field Col. Mus. Pub., Zool. Ser., v, 86, 1904, Rivers of 

 Isthmus of Tehuantepec on both sides of the divide. 

 Tetragonoptenis micro pthalmus Gtinther, Cat., v, 324, 1864, Lake 

 Amatitlan, Guatemala; Pacific Coast of Guatemala; Rio 

 Rimac. 

 Tetragonopterus hutnilis Gtinther, Cat., v, 326, 1864, Lake Amati- 

 tlan, Guatemala. 

 This species is exceedingly variable. In the material listed belo-w 

 I am unable to recognize but one species. 



El Rancho (80), 70 to 130 mm.; Los Amates (35), 55 to 85 mm.; 

 Lake Amatitlan (46), 50 to 120 mm.; San Jose del Idolo (35), 55 to 

 120 mm.; Caballo Blanco (43), 55 to no mm. 



Roeboides guatemalensis (Gunther). 



This species is quite abundant in lowland streams or bayous where 

 there is little or no current. 



San Jose del Idolo (100), 40 to 60 mm.; Caballo Blanco ; to 



85 mm. 



Brycon dentex Gtinther. 



None of the specimens taken by me was large. 



El Rancho ( \ ^'^ \t, to 1 23 mm ; Los Amates (2), 80 to 90 mm. 



Family GyniiiotitliP. 



Qymnotus carapo Linnaeus. Axguia. 



Two specimens from outlet of Lake Amatitlan are much darker 

 than a single individual in the collection from Los Amates taken by 

 Miller. 



Los Amates 170 mm., head 8.50; depth 10.00 in total length; 

 snout 2.79 in head; interorbital 2.67 ; greatest width of head 1.54. 



Outlet of Lake Amatitlan 146 mm.; head 8.14 in total length; 

 depth 9.15; snout 3.00 in head; interorbital 2.47 ; head 8.30 in total 

 length; depth 8.00; snout 2.77 in head; interorbital 2.38; greatest 

 width of head 1.43. 



These two specimens from Amatitlan are of a dark brownish color, 

 the smaller one has a few darker markings on ventral region, while the 



