132 SILUfilD^E. 



pointed, the lower rounded, contained six times and a half in the 

 total length. Uniform blackish. 



Guatemala. 

 a. Five inches long. Rio San Geronimo. From the Collection of 

 Messrs. Godman and Salvin. 



34. Pimelodus exsudans. 



Pimelodus exsudans, Jenyns, Zool. Beagle, Fish, p. 111. 

 D. 1/7. A. 13-14. P. 1/8. 



Head covered with thin skin above ; the occipital process does not 

 extend on to the basal bone of the dorsal spine and is rather short. 

 The length of the dorsal fin equals its distance from the adipose fin, 

 and is two-thirds of the length of the latter. The maxillary barbels 

 extend to the end of the ventrals, and the outer ones of the mandible 

 to the root of the pectoral. 



The height of the body is rather less than the length of the head, 

 and one-fifth of the total (with the caudal). Head with series of 

 large pores. Jaws equal in length. The eyes are somewhat before 

 the middle of the head ; their diameter is one-fifth of the length of 

 the head, and one-half of the width of the interorbital space. Pec- 

 toral spine serrated, long, but little shorter than the rays. Dorsal 

 fin higher than long ; caudal deeply forked, with the lobes equal in 

 length. {Jen.) 



? Eio de Janeiro. 



35. Pimelodus sapo. 



Pimelodus sapo, Valenc. in cT Orb. J'oi/. Amer. Merid. Poiss. pi. 2. figs. 6- 

 8 ; Cuv. iS" Val. XV. p. 179 ; Kner, Sitzgsher. Acad. Wiss. JVien, xxvi. 

 p. 417. 



D. 1/7. A. 11. 



Head covered with thin skin ; occipital process not reaching the 

 basal bone of the dorsal spine. Adipose fin and barbels very long. 

 The lower jaw is rather the longer. The diameter of the eye is two- 

 sevenths of the width of the interorbital space. Caudal fin deeply 

 forked. 



Eio de la Plata. 



36. Pimelodus hilarii. 



Pimelodus hilarii, Cuv. ?f Val. xv. p. 180. 

 D. 1/8. A. 12. 



Head covered with skin ; occipital process not reaching the basal 

 bone of the dorsal spine. Adipose fin long. The upper jaw is but 

 little longer than the lower ; the maxillary barbels extend somewhat 

 beyond the dorsal fin. ( Val.) 



Brazil. 



