254 THE FISHES OF MALABAR. 



Plates— Consist of hexagonal pieces with ctenoid margins, from the centre of each hexagon 

 six raised lines radiate towards its margins. 



Colours— Bright orange with numerous black spots along the sides, which are not situated 

 in the centre of the plates; some black spots also exist over the caudal and on the base of the 

 pectoral, the fins are yellowish, the abdominal surface of a whitish yellow. Pupil golden. 



Of the only two specimens taken in Cochin, the largest was not two inches in length. Dr. 

 Bleeker has fully described the Ostracion tesserula, and identified it as the young of the O. nanus, 



Bloch. 



Habitat — Seas of Malabar, Malaysia, and New Guinea. 



Ostracion tetragonus. 

 Ostracion tetragonus, Linn, Mus. ad Frider, p. 59, Atl. tab. 201, 203 ; Bleeker, Atl. 



Ich. v. p. 39, pi. 201, f. 2. 

 ? Ostracium nasus, Cantor, Catal. p. 369. 



B. vi. D. 9. P. 10. A. 9. C. 8. L. 1. 12. L. tr. 7. 



Length of head £, of pectoral -}, of caudal \, of base of dorsal T V> of base of anal T \ of the 

 total length. Height of head \, of body \, of dorsal 1 of anal \ of the total length. 



Eyes— Close to profile, diameter § of length of head, 2 diameters apart anteriorly, nearly 3 

 posteriorly, If diameters from end of snout. 



Body nearly quadrangular, profile from snout to forehead slightly convex, of back straight or 

 a little convex, back elongated, forming rather a long oval, and slightly convex owing to its being a 

 little highest along the mesial line. Hardly any nasal protuberance in a specimen b£> inches in 

 length. The height of the body is equal to the transverse width of the back, but the breadth of 

 the abdomen is slightly more. The vertical diameter of the sides is rather concave. Interorbital 

 space slightly concave. 



Lips fleshy. Nostrils close to anterior superior margin of orbit. 



Teeth— Nine to eleven, the six central ones being slightly the largest, but becoming blunted 



with age. 



Fins— The dorsal commences in the posterior fifth of the back opposite to the anus, but 

 rather before the anal fin, which last arises opposite its last ray. Caudal broad and triangular. 

 Pectoral broad and rather pointed. 



Plates— Consist of pentagonal, hexagonal, or heptagonal plates with finely serrated or ctenoid 

 margins, and covered with small bony tubercles arranged parallel to their margins. There are five 

 and two half-rows vertically on the sides. 



Colours— Greenish or yellowish olive, with one— rarely more— large dark spot generally in 

 the centre of each plate along the sides, on the back each has a white centre : about the snout 

 they are black and more numerous : the abdomen of a light colour. Fins transparent, with a 

 round brown mark on the base of the dorsal, and a few scattered spots or blotches over the caudal. 

 Eyes greenish yellow. 



This specimen was slightly above five inches in length, but it grows to more than a foot. 

 Habitat — Red Sea, Seas of India, and Malaysia to Japan. 



