384 TELEOSTEI 



Family Callichthyidae. The small mouth is ventral and provided 

 with minute teeth. The body is armoured with two rows of overlapping 

 bony plates which, like the surface of the cranial bones, are beset at 

 their hinder edge with movable denticles (p. 369). There is a strong 

 pectoral spine and an adipose fin. 



Gallichthys, L. ; Corydoras, Lac. — S. America. 



Family Loricariidae. These are closely allied to the last, but 

 (except in Arges) the bony plates are more numerous and form a com- 

 plete rigid armour on the head and body. The dermal bones are 

 studded with denticles and the small teeth resemble these in structure. 

 It is curious to note that the denticles may be much larger in the male 

 than in the female. The modified suctorial mouth is below the flattened 

 head, which generally develops a prominent lateral edge and snout (Figs. 

 374, 375). The orbits shift dorsally, the posterior nostrils moving close 

 to them. The parapophyses have disappeared, the pleural ribs are sessile, 

 and the anterior neural spines bifid. There is no adipose fin and the 



KlO. 374. 



Loricaria lancealata, Gthr. Uppei Amazons. (After Giiiither.) 



gill-opening is small, the opercular bones being also much reduced. The 

 pectoral spine is usually very large. The intestine becomes much 

 coiled. 



Sub-Family Arginae. With a naked body and strong ribs. 



Arges, C. and V. ; Astroblepus, Humb. — S. America. 



Sub-Family Loricariixae. With complete bony armour and 

 slender ribs. 



Plecostomus, Gthr. ; Chaetostomus, Heck. ; Loricaria, L. (Fig. 374) - r 

 Acestra, Kner — S. America. 



Family Aspredixidae. The head is wide and depressed, the body 

 naked and tapering to a long tail ; the gill-opening minute. The large 

 air-bladder is not enclosed by bone. The pectoral spine is very powerful. 

 Although the skelton resembles that of the Loricariidae in many points, 

 yet there is a leaning towards the Siluridae. There is a small dorsal 

 shield ; the bones of the operculum are vestigial, the opercular disappear- 

 ing altogether. The female carries the eggs embedded in the skin 

 below the head and belly. 



Aspredo, L. ; Bunocephalus, Kner; Dysichthys, Cope — S. America. 



