59. arius. 143 



their spine being two-thirds of the length of the head; ventrals 

 much shorter than pectorals. (Bl. ) 

 South-western coast of New Guinea. 



6. Arius arioides. 



Bagrus arioides, Cuv. fy Vol. xiv. p. 440. 



B. 6. D. 1/7. A. 21. P. 1/10. 



The length of the head is one-fifth of the total (with the caudal) ; 

 head one-fourth longer than broad. The maxillary barbel extends 

 to the hinder third of the pectoral, and the outer of the mandible is 

 nearly as long as the head. The teeth on the palate form two broad 

 triangles, joining each other anteriorly. Occipital process nearly as 

 broad as long ; the basal bone of the dorsal spine narrow, crescent- 

 shaped. Dorsal and pectoral spines entirely granulated ; the former 

 is slightly serrated behind, and one-fourth higher than the body, and 

 terminates in a longish soft filament. ( Vol.) 



Bengal. 



Blyth identifies this species with Pimehdus sona, Ham. Buch. 

 p. 172 (Journ. As. Soc. Beng. xxix. p. 151), to which opinion we do 

 not accede, as Buchanan, in his descriptions of Siluroids y always gives 

 the highest number of the anal rays, and says that P. sona has only 

 eighteen. 



b. South American species. 



7. Arius commersonii. 



Pimelodus barbus, Lacep. v. pp, 94, 106. 



commersonii, Lacep. v. pp. 95, 108. pi. 3. fig. 1. 



Bagrus barbatus, Quoy fy Gaim. Voy. JJran. Zool. p. 230. pi. 49. figs. 1 & 2. 

 commersonii, Valenc. in d 1 Orb. Voy. Amer. Merid. Poiss. pi. 3. 



fig. 1; Cuv. 8f Val. xiv. p. 449 ; Kner, Sitzunqsber. Acad. Wiss. Wien, 



xxvi. p. 386. 

 Pimelodus versicolor, Casteln. Anim. Amer. Sud, Poiss. p. 35. pi. 16. 



fig. 3. 



D. 1/7. A. 19. P. 1/11. 



The height of the body is one-fifth of the total length (without 

 caudal), the length of the head one-fourth ; the greatest 

 width of the head equals its length without snout. The 

 teeth on the palate are in a broad, long, horseshoe-like 

 band, scarcely interrupted in the middle. Six barbels ; 

 the maxillary barbels are as long as the head, the 

 outer mandibulary barbels extend to the base of the 

 pectoral. Crown of the head striated ; occipital process 

 elongate, elevated into a ridge along the middle, much 

 longer than broad ; the basal bone of the dorsal spine 

 is narrow, angularly bent. Dorsal spine of moderate 

 strength, as long as the head without snout, granulated 

 in front and scarcely serrated behind ; the soft dorsal 

 fin pointed, as high as the body ; adipose fin as long as 

 the dorsal. Pectoral spine serrated along both edges, 



