Evermanv and KeiulaJJ — Fish from Central Ecuador. 103 



sight. In captivity, as when under observation in a wash basin they make 

 use, after a while of their organ of locomotion, by climbing up the side of 

 the dish, out of the water, and shoving tluMiiselves along on the shelf or 

 the floor. They appear not to sutler as other fishes do when out of water, 

 as I have found them on the floor some hours after having left the water, 

 judging from lack of moist traces of their progress, quite active and shoving 

 themselves along by the aid of their sucker-mouth and the organ of locomo- 

 tion. This is a bony plate under the skin of the belly, freely movable for J 

 inch to 4 inch to which are attached 2 pairs of cord-like muscles, one pair 

 passing forward to near the junction of head and one pair endingjust forward 

 of the anal orifice. On eacli side of this plate is attached a ventral fin 

 moving with the plate and having its chief bone finely tuberculated, the 

 minute points of which tubercles, being directed backward, aid in locomo- 

 tion by engaging the surface over which the fish travels. 



The fish appears to be able to move over the ground or other surface in 2 

 ways, one when the mouth is fixed and the body brought forward by 

 being arched, when the mouth is loosed and the head advanced; the 

 second as when the roughened fin-bones act as a fixed point, the body 

 being shoved forward by a jerky motion by the contraction of the posterior 

 pair of nmscles, when the fins are then hauled forward by the anterior pair 

 of muscles to repeat the act. 



The food of this fish may be known by an examination of the stomach 

 contents and is determined naturally by the sort of supply furnished by 

 the locality of capture. Those from the quiet water of the bight of the 

 Alausi contained grains of sand, portions of aquatic plants, about a dozen 

 different forms of diatoms, and bunches of booklets, smooth and toothed, 

 the origin of which I do not know. 



The stomachs of the fish from the desert are stuffed with insect larvae of 

 various sorts, the same being very plentiful in those streams. I found no 

 diatoms in these specimens. 



In connection with the foregoing sketch l)y Dr. Davis, of his 

 observations in Ecuador, tlie following account by Humboldt of 

 the same region and fish may be of interest. Cuvier and Va- 

 lenciennes quote freely from it and add effusively to Humboldt's 

 description of the very remarkable phenomenon, the absurdity 

 of which must be apparent to every one. 



If is probably a fact that the fish have appeared on the plains 

 below the volcanoes after an eruption, but it is, of course, 

 unnecessary to explain that they probably were washed there 

 by the freshets of the mountain streams caused by the volcanic 

 or seismic disturbances. Humboldt say's : 



The volcanoes of the province of Quito eject pumice, basalt and porphy- 

 ritic scorite, and great quantities of carburetted water, and clay mud, which 

 spread to a distance of 8 or 10 miles. Yet the volcanoes of the district of 



