102 Evermann and Kendall — Fish from Central Ecuador. 



Humboldt says reaches a length of 14 inches. According to 

 Steindachner, Arges longifilis ranges from 9.5 to 18 cm. (about 

 3.8 to 7.2 inches). The other species of Arges and of Cyclopium 

 are small . Regarding the restriction of the species to the Pacific 

 slope of Peru, it may l)e said that most of the recorded localities 

 in which tlie different species of Arges and Cydopvum have been 

 ol)tained, are in the Atlantic drainage. Regan places all of the 

 species of the genus Arges excepting ri/rlopvm, 'whi/mperi, 

 eigeiiinaniii, clwUx', and smovsil in the Atlantic drainage, the 

 exceptions occurring only in the west coast streams of Peru and 

 Ecuador. Orton's specimens, which Putnam identified as G. 

 cyclopimi and which Regan says are the same as his Arges 

 eigenmaiDii are from lK)th drainages in Ecuador. Stygogenes 

 Jiiiniholdtl Giinther is from the Amazon basin in Ecuador. 

 Brontes prenadilla Cuvier & Valenciennes is from the east slope 

 of Cotopaxi. Our specimcnis are from l)oth slopes of the Andes 

 of Ecuador. 



Of the nineteen nominal species recognized l)y Regan, four 

 are exclusively of the west coast drainage, two at least are 

 common to Ijoth slopes, and the remainder restricted to the 

 Atlantic drainage. 



Habits. 



For the following interesting account of the habits of these 

 fishes we are indel)ted to Dr. Davis: 



The specimens from Alausi River were found in a bight made by 

 deviating the channel for purposes of railway construction. The stream 

 at the point mentioned has a fall of about 200 feet to the mile, and an ele- 

 vation above the sea of 9,400 feet. The water of the Alausi River reaches 

 the Pacific Ocean via the Guayas River. 



The specimens from Palmira Pass or Desert were taken from small 

 brooks flowing through deep channels cut in the volcanic deposits of 

 which the desert is largely composed, and were found in some instances 

 at the very sources of some of the rivulets, where the water seeps, spring- 

 like, from under the vertical walls of volcanic dust. These streams finally 

 reach the Atlantic through the Amazon River. The elevation of these 

 waters is about 10,500 feet and a strip of desert about 2 miles wide, and 

 perhaps 200 feet vertically, is all that intervenes between the headwaters 

 of streams on the Atlantic slope and the Alausi which does not come from 

 the desert but flows past its southern approacli and to the Pacific. 



The fish usually remain quietly on the creek bottom, sometimes in 

 eight but preferably under stones, aquatic plants or overhanging banks. 

 They are quiet unless disturbed, when they are active in getting out of 



