SILURID.E. 175 



head, 2 to 2 diameters from the end of snout, nnd from 3 to 4 

 apart. Head broader than high, its greatest width being equal to 

 its length behind the nostrils, the width of the mouth equals the 

 postorbital length of the head or a little more. Upper jaw the 

 longer, the angle of the mouth does not extend so far posteriorly 

 as to below the orbit. Upper surface of the head and occipital 

 process strongly granulated, the median longitudinal groove nar- 

 row and deep posteriorly and not quite reaching the base of the 

 occipital process, which is a little keeled, as broad at its base as it 

 is long or slightly broader, its anterior extremity slightly concave 

 and extending to the basal bone, which is V-shaped and rather 

 narrow. Barbels the maxillary reach the middle of the pectoral 

 fin, whilst the external mandibular pair are one fifth shorter. 

 Teeth villiform in two- somewhat widely separated triangular 

 patches/the vomerine being confluent with the palatine. Fins 

 dorsal spine very strong especially in its lower half, which is 

 granulated both laterally and anteriorly, serrated in its upper 

 portion, also posteriorly in its whole extent, it is nearly or quite 

 as long as the head and has a sofb prolongation ; base of adipose 

 dorsal shorter than that of the rayed fin, and equal to about half 

 the extent of the interspace between the two fins. Pectoral spine 

 as strong as, but rather shorter than, that of the dorsal, granu- 

 lated externally, serrated internally. Ventral not reaching the 

 anal. Upper caudal lobe sometimes the longer. Colour bluish 

 along the back and sides, becoming white beneath. Adipose dorsal 

 black, with its inferior and posterior margins yellow. Superior 

 portion of dorsal, the end of the pectoral and ventrals black, as is 

 also the anterior part of the anal. 



Hub. From Bombay through the Indian Seas to the Malay 

 Archipelago, not uncommon at Calcutta; attaining to a consider- 

 able size. 



182. (4.) Arras acutirostris. 

 Arius acutirostri?, Day, Fish. India, p. 459, pi. cvii, fig. 1. 



B. v. D. 1/7 | 0. P. 1/10. V. 6. A. 19 (5/14). C. 17. 



Length of head 3|, of caudal fin 6, height of body 7 in the total 

 length. Eyes diameter 7 in the length of head, 3 diameters 

 from the end of snout, and 2 apart. The greatest width of the 

 head equals about half its length, and is one sixth more than its 

 height. Snout fleshy and elongated, extending some distance 

 beyond the mouth ; mouth inferior, the extent of its gape equalling 

 one third of the length of the head. Upper surface of the head 

 granulated, or with roughened lines. Median longitudinal groove on 

 head not extending to the base of the occipital process, which is slightly 

 keeled, is rather longer than wide at its base, and reaches the 

 narrow V-shaped basal bone of the dorsal fin. Barbels short, 

 the maxillary reach beyond the hind edge of the eye; the outer 

 mandibular are about one third of the length of the head ; the 



