ARMOURED CAT-FISHES. 



115 



origin and is not constituted of modified muscles as is the case in 

 the Electric Eel (315, Wall-case 8). 



Callichthys (384, and fig. 57), a small fish of the rivers of the 

 northern parts of South America, is remarkable for the cuirass 

 which covers in the whole of the soft parts of the body. The 

 armour consists of an upper and a lower row of large, overlapping 



Fig. 57. — An armoured Cat-fish, Callichthys Uttoralis. 



shields on each side, each shield being much higher than wide. 

 The adipose fin is supported anteriorly by a short, movable spine. 



In the Loricariidse and Aspredinidse (Wall-case 10, floor) there 

 is a resemblance to the Siluridse in the absence of scales, the 

 fusion of the parietal bones with the supraoccipital, the absence of 

 the symplectic bone, and the presence of barbels and an adipose 

 fin, but there is a difference in the ribs being sessile upon the 

 centra of the vertebrae and not supported on transverse processes. 

 In the Loricariidse the mouth. is inferior, with circular lips, and 

 feeble dentition. In the forms like Plecostomus (387) and 

 Loricaria (386), which have a body cuirass of bony plates, the ribs 

 are slender, but in those which have an unprotected skin the ribs 

 are strong. The Loricariidse are confined to tropical and sub- 

 tropical parts of Central and South America. Many are of small 

 size ; the males of some species have a bearded or bristly snout. 



In the Aspredinidse the mouth is terminal ; the head is much 

 flattened ; there are no scutes ; the tail is slender. Aspredo 

 (390), of the Guianas, is the largest of the genera. The female 

 attaches the eggs to the under surface of her body by pressing 

 upon them, when they become embedded in the skin, which is 



i2 



Lori- 

 cariidas. 



Aspredo, 



