238 A HISTORY OF FISHES 



Exostoma, etc.) have the Hps reflected even more outwards and 

 backwards, these structures being provided with folds, ridges, or 

 papillae on their inner surfaces, and spread continuously round 

 the mouth in the form of a broad, flat sucking disc. The 



Fig. 93- 



A, B. " Capitane " (Cyclopium marmorata), X about ^ ; c. Section of a pot-hole 



22 feet deep in Santa Rita Creek, Colombia, showing the fishes ascending the 



rocky walls. (After Johnson.) 



Loricariids of the Andes {Cyclopium) have a similar sucker-like 

 mouth, which, in conjunction with an apparatus formed by 

 the lower surfaces of the pelvic fins, also serves as an organ of 

 locomotion (Fig. 93A, b). By means of the alternate action of 

 the mouth and of this apparatus the fish is able to creep slowly 

 forward against even a rapid current, and has been observed 



