t>4. -M.URICHTHYS. 179 



Silurus bagre, L. Syst. Nat. p. 505. 



Galeichthys gronovii, Cuv. 4" Vol. xv. p. 40; Kner, Sitzgsber. Wien. 



Acad. xxvi. p. 392. fig. 8 (air-bladder). 



eydouxii, Cuv. fy Val. xv. p. 43. 



Bcgrua macronemus, Ranzani, in Nov. Comm. Acad. Sc. Inst. Bonon, 



1842, v. p. 334. tab. 28. 

 Mystus carolinensis, Gronov. Syst. ed. Gray, p. 156. 



B. 6. D. 1/7. A. 29-32. P. 1/12. 



The maxillary barbels extend to, or beyond, tbe anal. Pectoral 

 and dorsal spines of nearly equal length, shorter than the head. The 

 teeth on the palate form a band, which is slightly interrupted in the 

 middle and on each side of the vomer. 



Tropical America. 



a. Half-grown. Demerara. Presented by Dr. Hancock as Pimelodus 



buer%i. 



b. Half-grown. South America. Presented by Sir R. Schomburgk. 

 c-d. Half-grown and young. West Indies. Purchased of Mr. 



Scrivener. 

 e-f. Half-grown : stuffed. West Indies. Purchased of Mr. Scrivener. 

 (j. Adult. Purchased of Mr. Frank. 

 h. Half-grown. 



/3. A large subquadrangular buckler on the nape. 

 4. JElurichthys nuchalis. 

 D. 1/7. A. 26. P. 1/12. 



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

 which is two-ninths of the total (without caudal) ; the greatest 

 width of the head is three-fourths of its length ; snout longer than 1 

 the eye, the diameter of which is rather less than one-fourth of the 

 length of the head. The vomerine band of teeth is separated in the 

 middle by a short interspace, each half being as broad and long as 

 the palatine band with which it is subcontinuous. The maxillary 

 barbels extend to the root of the ventral, those of the mandible 

 nearly to the pectoral. The dorsal buckler is as broad 

 behind as in front, with rounded lateral margins, each 

 half being bent downwards on the side. Dorsal fin 

 narrow and elevated, the first ray being considerably 

 longer than the spine, which is as long as the head 

 without snout ; pectoral spine equal to the dorsal spine. 

 The origin of the anal fin is much nearer to the base 

 of the caudal than to that of the pectoral. The first 

 pectoral ray is produced into a long filament reaching beyond the 

 origin of the anal. Ventrals extending beyond the vent, their length 

 being three-fifths of that of the head. Iridescent blue above, silvery 

 below. 



Pacific coast of Panama. 

 a. Fine specimen, 11 inches long. From the Collection of Messrs. 

 Godman and Salvin. 



This species is perhaps closely allied to ASlurichihys panametisis, 



' n2 



