THE FISHES OF MALABAR. J 79 



Eyes — Oval, situated midway between the posterior extremity of the opercles and the end <>\' 

 snout. Horizontal diameter j , vertical diameter £ of length of head, 1 diameter from end of snout, 

 - diameters apart. 



Mouth wide, upper jaw rather the longest. Maxillary cirrus extends to half the length "I' tin- 

 pectoral, the two mandibular cirri to its base. Opercle striated in rough lines. Central longi- 

 tudinal groove of head broad, extending in front to the snout, and behind to opposite the posterior 

 extremity of the opercle. Occipital process longitudinally keeled, narrow, one and a fourth times 

 as high as wide, basal bone narrow, both covered with nodules — most apparent in the adult— as 

 is also the skull as far forwards as the orbits, and laterally as the opercles. Shoulder bone also 

 similarly roughened. Nostrils, the posterior the largest, oval, and with a valve : the anterior 

 round, close to the anterior margin of the snout. 



Teeth — In intermaxillaries villiform and numerous in a band about a sixth as wide as long, and 

 which is rather expanded at its extremity. They are also villiform in the mandibles. In either 

 palatine bone is an irregularly triangular patch containing numbers of vilhform teeth, they are 

 nearer together anteriorly, than posteriorly. 



Fins — Dorsal commences opposite the centre of the pectoral ; ventral midway between the 

 snout and base of caudal : anal midway between the base of pectoral and the posterior extremity 

 of the lower lobe of the caudal. Dorsal pointed, spine in the adult much thicker below than 

 above, but weaker in the young ; anteriorly granulated in its basal half, and semi- 

 serrated in its upper portion : serrated posteriorly, laterally compressed and rough : its rays 

 rapidly decrease in length to the last ; its spine equals the distance from the posterior extremity of 

 the opercle to the posterior extremity of the anterior nostril. Pectoral spine rather shorter and not 

 so strong as the dorsal, it is laterally compressed, roughened anteriorly, and serrated posteriorly. 

 The sixth anal ray the longest, its external margin concave. Caudal deeply lobed. 



Lateral line — Consists of short parallel longitudinal tubes. First it rises slightly to the upper 

 fourth of the body, opposite the first dorsal spine it curves downwards, and then nearly above the 

 commencement of the anal it proceeds straight : at the base of the caudal it divides into tw< > 

 branches, the upper crossing the base of three rays, and the lower the base of two. 



Air vessel of a silvery tint, with a thick fibrous covering, and very adherent. The lining- 

 membrane is very thin. 



Colours — In the adult steel blue, with a gloss of golden. Adipose fin black, with its posterior 

 margin yellow. Dorsal, anal, and caudal grey, finely spotted with minute black points, as is alsi i 

 the under surface of head and abdomen. Upper surface of head blackish. The young have no 

 black spot to the adipose dorsal. 



Grows to eleven inches or more. 



Habitat — Seas of India, Burmah, and Malaysia. 



Arius GAGORA. 



Pimelodus gagora, Ham. Bach. pp. 167, 376, pi. 10, f. 54. 

 Arius gagora, Ctw. & Vol. xv. p. 99 ; Gunther, Catal. v. p. 168. 



B. v. D. J | 0. P. ioJrr- V. G. A. 18-19. C. 15. Vert. if. 



Length of head f , of caudal T ^-, of base of first dorsal ^j, of base of second dorsal ,-',;, of base 

 of anal ^ of total length. Height of head f.., of body |, of first dorsal J, of anal ' of total 

 length. 



2 a 2 



