1 8 4 9 .] Catalogue of Malayan Fishes. 1367 



rounded ; the first ray is situated nearly in the centre between the 

 muzzle and the caudal ; the first five rays are undivided, and with the 

 succeeding ones gradually increase in length to the 14th and 15th, which 

 are the longest, ^ the length of the head ; the extent of the base is con- 

 tained 3} times in the total length, of which latter the distance from the 

 caudal is i. The anal commences opposite the second third of the 

 dorsal, which it resembles in form ; the two first rays are undivided ; 

 the 10th and 11th rays are the longest, a little shorter than the 14th 

 and 15th dorsal. The extent of the base is a little less than the length 

 of the head ; the fin terminates a little behind the dorsal. The three 

 margins of the caudal are a little convex ; the length slightly exceeds ^ 

 of the head. The pectorals are broad oval ; their length is about ^ of 

 the head. The spines are strong, distant, upwards pointed and scarcely 

 longer than their two oblique roots. They are placed so as to form a broad 

 belt, the superior margins of which commence behind the orbit, and pro- 

 ceed straight to a little behind the pectorals ; from thence the posterior 

 margin encircles the abdomen to within a short distance of the anus, 

 which is situated opposite the commencement of the dorsal ; the anterior 

 margin follows the posterior part of the cheek and then proceeds obliquely 

 forwards behind the throat. The rest of the body is perfectly smooth, 

 without abdominal keel. During life the lateral line is very indistinct, 

 On the vertex and the cheeks appear several anastomosing lines, 

 which on each side continue in three undulating lines : one close to the 

 back, a second in the middle, and a third near the abdomen ; all three 

 terminate at the root of the caudal. Three individuals, varying from 

 4 1 to 10 inches in length, were observed at Pinang in February and 

 November 1844, and in July 1845. The enlargement of the upper 

 and under interspinous bones of the tail, described by Richardson, 

 is no constant character. It existed in none of those examined at 

 Pinang, but one of them had an isolated osseous tubercle in front of 

 the anal, another had a similar in the middle of the left side. Like 

 Harpochirus punctatus and Platax arthriticus the present species ap- 

 pears to have a tendency to hypertrophy of the bones. 



All the preceding species of Tetrodon are capable of inflating the 

 abdomen, and in this state, when taken or handled, they emit a grating 

 sound, They are also remarkable for tenacity of life, which they are 



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