166 SILURID.E. 



49. Arius polystaphylodon. 



Ariu8 polystaphylodon, Bleek. Verh. Bat. Gen. xxi. Silur. Bat. p. 40. 

 A-riodes polystaphylodon, Bleek. Prod?: Silur. p. 90, and Atl. Ichth. 

 Silur. p. 41. tab. 60. fig. 3. 



B. 6. D. 1/7. A. 15-16. P. 1/12. 



The height of the body is rather less than one -fifth of the total 

 length (without caudal), the length of the head two-sevenths. Head 

 granulated above ; the occipital process is triangular, much longer 

 than broad, with the lateral margins convex. The teeth on the 

 palate are obtusely conical, arranged in four patches : a small ovate 

 patch on each side of the vomer, and an elongate patch along each 

 palatine bone ; the palatine patches slightly divergent behind. The 

 maxillary barbels extend to the root of the pectoral. Dorsal fin 

 rather higher than the body ; its spine is of moderate strength, 

 slightly serrated behind, and three-fifths of the length of the head. 

 The pectorals are much shorter than the head, and their spine is 

 scarcely longer than that of the dorsal fin. 



Java and Sumatra. 



a. Type of the species : very bad state. From Dr. P. v. Bleeker's 

 Collection. 



50. Arius goniaspis. 



Arius goniaspis, Bleek. Act. Soc. So. Ltd. Neerl. iii. Sumatra, vi. p. 44. 

 Ariodes goniaspis, Bleek. Prodr. Silur. p. 01, and Atl. Ichth. Silur. p. 42. 

 tab. 60. fig. 1. 



B. 6. D. 1/7. A. 16. 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 two-fifths or 

 thrice and three-quarters. Head granulated above ; occipital pro- 

 cess triangiilar, with the lateral margins straight, broader than long. 

 The teeth on the palate are granular, arranged in four groups : a 

 small ovate patch on each side of the vomer, and a flat elongate 

 patch along each palatine bone ; the palatine patches divergent be- 

 hind. The maxillary barbels extend to the extremity, the outer 

 ones of the mandible to the base, of the pectorals. Dorsal fin rather 

 higher than the body ; its spine is of moderate strength, but slightly 

 serrated, and three-fourths or three-fifths of the length of the head. 

 The length of the pectorals is three-fourths or five-sixths of that of 

 the head ; their spine is similar to that of the dorsal fin. 



Sumatra. 



a. Young. Type of the species. From Dr. P. v. Bleeker's Col- 

 lection. 



b. Teeth on the palate in two groups. 

 a. East Indian species. 



51. Alius maculatus. 



PSilurus maculatus, Thunh. Vet. Acad. Nya Handl. 1792, xiii. n. 31. 

 taf. 1. fiff. 2. 



