1 849*] Catalogue of Malayan Fishes. 1 33 1 



Monacanthus geographicus, Swainson, II. 327. 

 Ground-colour pale greenish blue with scattered small brown spots ; 

 from the anterior part of the base of the posterior dorsal to behind the 

 eye an oblique, undulating, lilac brownish band, edged with whitish, and 

 with numerous small brown spots ; a second similar from the middle 

 of the base of the posterior dorsal to beneath the pectorals ; a third 

 from the posterior part of the latter fin and the tail to the anus ; these 

 bands are frequently interrupted or broken up, so as to make the body 

 resemble a geographical chart of islands ; from the anterior part of the 

 orbit three or four short radiating brownish bands ; first dorsal spine 

 greenish blue, indistinctly annulated with brown ; membrane pale lilac 

 clouded and minutely dotted with brown ; rays of posterior dorsal, 

 caudal and anal pale greenish blue ; their membranes pale brownish 

 lilac transparent ; basal half of dorsal with three or four parallel undu- 

 lating brown lines ; anal with a dark brown net- work ; anterior two 

 thirds of caudal with numerous brown dotted lines, parallel to the 

 posterior margin, near which 6 or 7 pale blackish lilac confluent lines ; 

 lower part of the dewlap pale whitish lilac with small brown spots. 

 Iris frosted silvery, with indistinct radiating brownish bars. 



D 2—29, 31 or 32, C 10±, A 29, 30, 31 or 32, P 13 or 12, Br. V. 

 Habit. — Sea of Pinang, Singapore, Malayan Peninsula. 

 Total length : 8f inch. 



When the pelvic spine is withdrawn, the form of the body is nearly 

 rhombic. The length of the head, from the muzzle to a little behind the 

 orbit is contained 3^ times in the total. The eye is situated at a short dis- 

 tance beneath the first dorsal spine ; the posterior margin of the orbit is 

 immediately above the'gill-opening ; the horizontal diameter of the eye is 

 contained 4 J times in the length of the head. The outline of the forehead 

 is concave, ascending towards the first dorsal spine ; angular from side 

 to side ; the horizontal distance between the eyes equals one diameter. 

 The nostrils, lips, teeth and tongue resemble those organs of Balistes 

 conspicillum. The four upper branchiostegous rays are slender like 

 hairs, the fifth is broad, sabre-like, with the upper margin elongated ; it 

 appears like two soldered together ; the first dorsal spine is strong and a 

 little backwards arched ; the anterior surface is rounded, longitudinally 

 furrowed and very prickly ; the posterior is smooth, with about 7 strong 

 downwards directed thorns on each side ; the length of the spine equals 



