1330 Catalogue of Malayan Fishes. [Dec. 



When the pelvic spine is withdrawn, the outline of the body is 

 elongated oval. The length of the head, from the muzzle to a little be- 

 hind the orbit, is contained 3\ times in the total. The eye is situated at 

 a little distance beneath the first dorsal spine, and above the pectorals 

 and gill-openings ; the horizontal diameter is £ of the length of the head 

 and equals the distance between the eyes. The nostrils, lips, teeth 

 and tongue resemble those organs of Balistes conspicillum. The first 

 dorsal spine rises above the eye ; it is moderately strong, slightly arched 

 and serrated both on the anterior and posterior margin ; it is a little 

 less than % of the length of the head ; the second spine is very slen- 

 der, like a bristle and flexible, ^ of the length of the former. Their 

 connecting membrane extends but little behind the orbit ; its distance 

 from the posterior dorsal equals the length of the first spine. The first 

 four rays of the posterior dorsal gradually increase in length ; the fifth 

 ray, from which the rest very slowly decrease, is but little longer than 

 the horizontal diameter of the eye ; the extent of the base is -f of the 

 length of the head ; the distance from the caudal is J- of the extent of 

 the base. All the rays of the posterior dorsal, the anal and the pecto- 

 rals are undivided and spinous on their sides. The caudal is elongated, 

 with the posterior margin rounded ; all the rays except the upper and 

 lower, are divided ; the length of the central ones is f of the head. 

 Although the anal commences a little in front of the posterior dorsal, 

 the extent of its base is not longer ; in other respects it resembles the 

 dorsal. The pectorals are rounded, ^ of the length of the head. The 

 point of the pelvic spine barely projects beyond the integuments ; the 

 spine is large, arched ; f of the length of the head ; it is very protrac- 

 tile, forming the anterior margin of the triangular dewlap ; the base of 

 the latter equals this margin ; but the posterior margin is shorter by J. 

 The vertical diameter of the protracted dewlap is contained 2| times in 

 the total ; in front of the posterior dorsal it is \ of the total. The 

 whole body has a downy appearance from being covered with minute 

 prickles, rough to the touch ; those of the tail are a little longer than 

 the rest. A solitary individual occurred at Pinang in July, 1844. 



MoNACANTHUS GEOGRAPHICUS, (Peron.) 



Balistes geographicus, Peron. 



Monacanthus geographicus, Cuv. R. A. II. 373 ('), PL XI. Fig. 2. 



(Young.) 



