SILURIDJ;. 179 



less. Upper jaw the longer, the width of the gape of the mouth 

 half the length of the head. The median longitudinal groove on 

 the head shallow, extending to a little behind the posterior edge of 

 the eye. Upper surface of the head granulated in radiating lines. 

 Occipital process one half wider at its base than it is long, its 

 posterior extremity rounded where it meets the basal bone of the 

 dorsal fin, which is large and somewhat butterfly-shaped. Barbels 

 the maxillary reach to the middle or end of the pectoral spine, the 

 outer mandibular to its base or middle. Teeth ou the palate in 

 two confluent villiform patches on either side, meeting in the 

 mesial line, each of these patches has a convex inner edge. Fins 

 dorsal higher than the body, the spine strong and as long as the 

 head excluding the snout, granulated or serrated anteriorly, serrated 

 posteriorly ; the base of the adipose nearly as long as that of the 

 rayed fin. Pectoral spine stronger than that of the dorsal and 

 equally long, serrated externally along its outer fourth and denticu- 

 lated internally, its outer ray often prolonged. Ventral nearly 

 reaching the anal. Upper caudal lobe the longer. Colour greenish 

 brown, becoming lighter on the abdomen ; some specimens have 

 narrow vertical bands of spots on the body. Fins tinged with 

 dark. 



Hub. From Bombay through the seas and estuaries of India to 

 the Malay Archipelago. Said to be very common at Batavia, 

 where it is largely consumed. This species attains to at least 3 

 feet in length. 



188. (10.) Arms sona. 



Pimelodus sona, Ham. Buck. Fish. Ganges, pp. 172, 376. 

 Arius sona, Day, Fish. India, p. 462, pi. cv, fig. 2 (see synon.). 



B. vi. D. 1/7 | 0. P. 1/12. V. 6. A. 17 (6/11). C. 17. 



Length of head 4, of caudal fin 5 to 6, height of body 6 in the 

 total length. Eyes diameter 7 to 9 in the length of head, 2| to 

 3 diameters from end of snout, and 3| to 4| apart. Head one 

 half broader than high, and almost as wide as long. Upper jaw 

 the longer ; the extent of the gape of the mouth equal to two 

 thirds of the length of the head. Median longitudinal groove on 

 the head wide, but not extending so far as the base of the occipital 

 process ; the latter keeled, convex at its posterior extremity where 

 it reaches the basal bone of the dorsal fin which is somewhat narrow, 

 especially in its centre, while each side is slightly bent into an S- 

 shaped form. The occipital process is as wide at its base as it is 

 long or rather wider ; it and also the crown of the head from behind 

 the eyes are granulated, these granulations have somewhat of a 

 radiating direction. Barbels the maxillary reach to the end of 

 the head, the outer mandibular are shorter. Teeth on palate 

 villiform, those on each palatine in a large somewhat triangular 

 patch which is emarginate posteriorly, anteriorly two small patches 

 on the vomer connect the two palatine ones together. Fins 

 dorsal spine strong, granulated anteriorly, serrated posteriorly, and 

 as long as the head excluding the snout, but not so high as the 



N2 



