SOUTH AMERICAN NEMATOGNATHI.' 169 



7. PleCOStomuS plecostomus (Linnaeus.) 



H. guacari Lacepede; L. Jlaua Shaw; H. veres Cuv. & Val.; PI. bi- 



cirrhosus Grouuw.; PI. brasiliensis Bl. 

 Localities: Silva, Lake Saraca; Para; Hyavary; Coary; Rio Puty. 



8. Plecostomus vaillanti Steludachner. 



Localities: Kio Puty; Kio Preto; San Goncallo. 



9. Plecostomus villarsi Lutken. 



10. Plecostomus virescens Cope. 



11. Plecostomus biseriatus Cope. 



12. Plecostomus seminudus uov. 



Type: A single specimen. Locality: Brazil? 



13. Plecostomus annse Steindachner. 



14. Plecostomus pantherinus (Kner. ) 



nn. Head with round spots; ventral surface 

 plain. villarsii 9. 



II. Ventral surface more or less naked. 

 0. Lower surface of head naked. 



virescens 10. 

 00. A quadrate naked space between the 

 ventrals. biseriatus 11. 



000. Belly with scutes on the sides, and 

 sometimes a narrow strip between ven- 

 trals. 



p. Lat. 1. 27. Upper lateral plates with 

 strong median keel; head with strong 

 occipital and weaker temporal keels; 

 nuchal plates bicarinate. A baud be- 

 tween the pectorals, sides of the belly 

 and a narrow median area between the 

 ventrals covered with scutes. Dorsal 

 surface, sides and fins spotted with 

 brown; ventral surface plain. 



se7ninudus nov. 12. 

 pp. Lat. 1. 30; lateral plates not keeled. 



a?mcE 13. 

 0000. Belly entirely naked, pantherinus 14. 

 dd. Head without distinct ridges or keels; snout broad, rounded. 

 g. Belly covered with granular plates. 

 r. Tip of snout naked. ,\\ 



s. Dorsal crossed by six or seven black zig-zag stripes. 



\ cordovce 15. 



