THE FISHES OF MALABAR. 23 



Genus, DIAGEAMMA, Cuvier. 

 Plectoriiynchus, Lacep. 



Branchiostegals, sis or seven : pseudobrancbiffl. Body oblong, compressed, with the upper profile of 

 head parabolic. Eyes of moderate size. Mouth small, horizontal, with lips folded and turned back. Four 

 or six pores on under surface of lower jaw, but no large groove. One dorsal with from nine to fourteen 

 spines, anal with three. Preopercle serrated, suborbitals entire. No canine teeth. Scales rather small, 

 rarely of moderate size. Air bladder simple. Pyloric appendages few. 



DlAGRAMMA NIGRUM. 



Pristipoma nigrum, Cantor, Catal. p. 74 ; ? Guv. & Vol. v. p. 258 ; Guntlur, Catal. i. 



p. 289. 

 Diagramma affine, Giinther, Catal. i. p. 319. 



B.vii. D. \$. P. 16. V. i A. f. C. 17. L.l. 47. L.tr.tf. 



Length of head f , of pectoral \, of caudal \, of base of dorsal } 2 , of base of anal \ of total 

 length. Height of bead \, of body 1-, of bard dorsal \, of soft dorsal fa, of ventral J, of anal T 2 T of 

 total length. 



Eyes— Transversely oval, horizontal diameter \, vertical diameter \ of length of bead, 1| 

 diameter from end of snout, more than 1 diameter apart. 



Lips fleshy, folded, and turned back. Snout short, rather elevated. Cleft of mouth horizontal, 

 rather narrow. Maxilla extending only two-thirds of the distance to the orbit, in young specimens 

 it goes rather further back. Nostrils approximating, situated close to anterior superior margin of 

 orbit. Preopercle, vertical Hmb finely serrated, angle rather produced, rounded and denticulated, 

 also about half the horizontal limb sparingly denticulated. Sub- and interopercles and preorbital 

 entire. Opercle with two bluntisb spines, the lower of which is the largest and serrated. Supra- 

 scapular serrated : scapular and coracoid bones entire. 



Teeth — Two vilbform bands in either jaw separated by a narrow interspace. 



Fins— Dorsal with a scaly sheath, the base of spinous portion two-thirds the entire length of 

 that of the fin. Spines strong, interspinous membrane deeply notched. The thickness of each 

 spine varies on the different sides of the body, the fourth the longest. Ventral spine moderately 

 strong. Anal arises opposite third or fourth dorsal ray, the spines which are very strong have a 

 scaly sheath at their base, the second much the strongest, more than two and a half times as long 

 as the first, and one-third longer than the last. Pectoral rounded. Ventral and caudal both 



moderately rounded. 



Scales— Above lateral Hne passing obliquely upwards and backwards, below it in horizontal 



rows : the whole of the head except the snout scaled. 



Lateral line— In upper third of body, passing parallel with the back until opposite end of 



soft dorsal. 



Air bladder large : intestinal canal short, pyloric appendages rather numerous. 



Colours— Generally greyish or slate colour, with a golden brassy tint towards the back and 

 abdomen, and a violet tinge over the bead and remainder of the body, especially about the fore- 

 head. A few bright coppery spots are irregularly dispersed over some scales, and a coppery tinge 

 over the bard rays of the dorsal. All the fins of a violet slate colour, stained darker along their 

 margins, and with a dark band at the base of each, so that the centre is the lightest colour. Throat 

 and breast white. Eyes silvery, with a copperish dash. 



