1U4- 



silurid^:. 



the pectoral. The soft dorsal fin is rather higher than the body ; 

 its spine is strong, two-thirds as long as the head, and finely serrated 

 along both edges. The pectoral spine is somewhat shorter, and not 

 stronger, than that of the dorsal. Adipose fin very short. Colora- 

 tion uniform. 



Zambesi. 

 a. Skin, 8 inches long. Shupanga. Presented by Dr. Kirk. 



45. Arius tonggol. 

 Arms tonggol, Bleek. Verh. Bat. Gen. xxi. Silur. Bat. p. 48. 



crossocheilos, Bleek. I. c. p. 4G. 



Anodes tonggol, Bleek. Prodr. Silur. p. 83, and Atl. Ichih. Silur. p. 39. 

 tab. 57. 



D. 1/7. A. 18. P. 1/11. 



The height of the body is contained five times in the total length 

 (without caudal), the length of the head thrice and a half or thric* 

 and four-fifths ; head depressed, much broader than high, its width 

 being two-thirds of its length. The occipital process is triangular, 

 with the sides convex, a little longer than broad, 

 and much elevated along its middle ; basal bone 

 of the dorsal spine small. Teeth on the palate 

 granular, forming four separate groups : two 

 small ones on the vomer, and one oblong on each 

 palatine : those on the vomer are half as large as 

 the eye. The palatine bands convergent behind.. 

 The maxillary barbels extend to the operates. 

 The soft dorsal fin is rather higher than the 

 body ; its spine is of moderate strength, its 

 length being contained once and a third in that 

 of the head ; it is granular in front, and serrated 

 behind. Adipose fin shorter than the dorsal ; 

 the pectoral spine is stronger than, and as long 

 as, that of the dorsal fin. Pins yellowish. 



Java, Sumatra, Bintang, Banka. 

 a. Type of the species. From Dr. P. v. Bleeker's Collection. 



46. Arius argyropleuron 

 Arius argyropleuron, (Kuhl 8f van Mass.) Cuv. Sf Val. xv. p. 104. 



acutus, BUek. Verh. Bat. Genootsch. xxi. Siluf. Bat. p. 41. 



<- hamiltonis, Bleek. I. c. p. 47. 



Ariodes acutus, Bleek. Prodr. Silur. p. 8/. 



argyropleuron, Bleek. Atl. Ichth. Silur. p. 40. tab. 59. 



This species agrees with A. tonggol in almost every point, but the 

 vomerine teeth are reduced to a rudimentary, minute patch on each 

 side ; and the lateral margins of the occipital process are straight 

 instead oi being slightly convex. 



Java and Sumatra. 



a. Adult. From Dr. P. v. Bleeker's Collection. 



b. Half-grown. From Dr. P. v. Bleeker's Collection. — Type of Arius 



acutus. 



