SOUTH AMERICAN NEMATOGNATIII. 451 



depressed, margined Avith bristles in front of the pre- 

 opercle. Caudal forked. 



443. Scleromystax barbatus. 



Callichthys barbaitis Quoy & Gaimard, "Voy. Uran. Zool. 234;" 

 Cuv. & Val. Hist. Nat. Poiss, xv, 322, 1840 (Eio Janeiro); Giin- 

 ther, Cat. Fish. Brit. Miis. v, 229, 1864 (copied). 



Schromystax barbatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 

 i, 164, 1888 (name only). 



Habitat: Kio Janeiro. 



Mouth very small, protractile; maxillary barbels reach- 

 ing to the middle of the opercle; Sazygous shields before 

 the adipose fin. 



Dorsal and anal with blackish spots. D. I, 6; A. 7; 

 Lat. plates ||. (Quoy & Gaimard.) 



XCVI. Callichthys. 



Callichthys Linnaeus, Amcen. Acad, i, 317, 1754. 



Callichthys Cuv. & Val. Hist. Nat. Poiss. xv, 294, 1840 

 (asper^ callichthys). 



Callichthys Bleeker, Nederl. Tijdschr. Dierk. i, 82, 1863 

 (tainoata=^ callichthys). 



Cataphractus Bloch, Ausl. Fische, viii, 80, 1794 (pre- 

 occupied in Mammals). 



Cataphractus Lacepede, Hist. Nat. Poiss. v, 124 (call- 

 ichthys). 



Cataphractus Swainson, Fishes, Reptiles, etc., ii, 304, 

 1839 (de.pressiis=^callichthys). 



Type: Silurus callichthys Linnaius. 



Habitat: La Plata to Trinidad. 



ANALYSIS OF THE SPECIES OF CALLICHTHYS. 



a. Lateral plates ffzly; barbels reaching beyond the gill-opening. 



callichthys 444. 



oci. Lateral plates ff ; inner barbel reaching to the eye, the outer one 

 shorter; a series of small spines in front of the adipose fin; light brown, 

 with small darker spots. D. 9; A. 7. (Hensel.) arcifer 445. 



