668 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXI. 



NOTP: ox a PARAGUAYAN FISH. 



PIMELODUS CLARIAS (Bloch). 



Four specimens haven number of characteristics in common. These 

 have the humeral spine a little more convex on the dorsal marg-in than 

 the ventral margin, but without distinct notches. The dorsal plate is 

 composed of two elements, the anterior of which is separate from the 

 posterior in the young and shows a suture in the adult. The adipose 

 tin is contained 4f times in the length of the fish. 

 The dorsal plate is long, and measures at least 

 twice as much along the median line as along the 

 sides. 



The specimens are all faded and worn. The 

 upper dorsal membranes are dusk}", the dorsal 

 margin blackish. 



The foregoing notes relate to specimens Nos. 

 1552, 1556, and 1616, U.S.N.M. 



Specimens in the Indiana Universit}" Museum, 

 No. 9828 from Paraguay, and No. 9276 from 

 Iguape, showing otherwise the same character- 

 istics as those above mentioned, have the sides 

 and back with several series of small spots, which 

 extend on the caudal fin. 

 Another specimen differs notabl}" from an}' of those described 

 above. The dorsal margin of the humeral plate is very different from 

 the ventral; its middle third is concave, the concave part being joined 

 to the very obliquely -descending posterior margin at a distinct angle. 

 The dorsal plate is very little longer along the median line than it is 

 on the sides, the suture between the two elements composing the plate 

 being much less conspicuous than in the preceding specimens. The 

 adipose is contained 5 times in the body length. The maxillary barbel 

 reaches to the end of the adipose. There are patches of teeth on the 

 pterygoids, and very minute ones on the vomer. 



Specimens «in Indiana University, Nos. 9826 and 10286 from Para- 

 guay, and No. 1268 from Tabatinga, that resemble this specimen except 

 in the length of the barbels, are bright silvery in color, without spots. 



Fig. 5.— Dorsal plate of 

 pimelodus ci.akias. 



