FISHES. 



113 



eastern part of Soutli America. The species reach a length of about eighteen 

 inches. 



The principal genus is Platystacus {Aspredd). The species of this group are 

 noted for the method in which the eggs are guarded after exclusion. Contrary to 

 the usual rule among fishes, this office is taken by the female. According to Dr. 

 Gtinther, " during the time of propagation, the lower side of the flat trunk of the 

 female \_Aspredo'] assumes a soft and spongy texture. After having deposited the eggs, 

 the female attaches them to, and presses them into, the spongy integument, by merely 

 lying over them. She carries them on her belly as the Surinam toad {Pipa) carries 

 her ova on her back. When the eggs are hatched, the excrescence on the skin disap- 

 pears and the abdomen becomes smooth as before." 



Fig. 77. — Loricaria catapliracta. 



The SisoEiD^ are small fishes from the mountain streams of farther India and 

 Besngal. They have a single dorsal fin, small eyes, reduced gill openings and naked or 

 mailed skin. In one genus, Pseudecheneis, a sucking disc, formed of transverse plaits 

 of skin, exists on the breast, between the pectoral fins, enabling the fish to resist the 

 current by clinging to stones. In another genus, Exostoma, the thick lips with 

 reflected edges foi-m a sort of sucking disc which serves a similar purpose. 



The LoEiCAEiiD^ (including Callichthyid^) are small cat-fishes from the fresh 

 waters of South America, east of the Andes. They have the small inferior mouth 

 and narrow gill openings of the preceding family, and, with few exceptions, the body 

 and head are entirely covered by a coat of mail made of interlocking bony plates. 

 The lips are thick, the barbels few and short, the dorsal fin well forward, the adipose 

 fin wanting, or supported by a stifE spine. More than a hundred species are known. 

 Of the genera, Loricaria is remarkable for the slenderness of its body : Chwto- 

 siomus and others, for the presence of a bunch of stiff erectile bristles or spines on the 



VOL. III. — 8 



