'). MO.VACANTHUS. 249 



opeuitig below the hinder half of the orbit ; pectoral fin behind the 

 vertical from the hind margin of the orbit. Dorsal spine strong, 

 very long, nearly as long as the head, situated above the posterior 

 half of the orbit ; it is armed behind with a double series of very 

 small barbs, and there is also a double scries of minute barbs in the 

 median line of the anterior surface of the spine. Caudal fin rounded, 

 short ; dorsal and anal fins low. Ventral spine very small, fixed, 

 with verj' short sj)ikcs radiating from its centre. Uniform blackish 

 brown, dorsal and anal fins yellowish. 

 Australia. 



a. Stuftcd, 14 inches long. Purchased of Mr. Cuming. 



2. The dorsal sj)me is fvur-edged, the edges being equidistant and armed 

 icith barbs. 



31. Monacanthus peronii. 



Monacanthus peronii, Hollard, Ann. Sc. Nat. 1854, ii. p. 356, pi. 13. 

 fig. 4. 



I). 33-35. A. 33. 



Body covered with papilla;, each with a round expansion at 

 the top, like a mushroom ; in examples exposed to the air for 

 some time they shrink, assuming the appearance of a spine. 

 Adult males with a band of long stiff slender spines on each side 

 of the tail between the dorsal and anal fins, like a tooth-brush. 

 Body oblong, its depth being contained twice and one-third in the 

 total length (without caudal). Snout produced, with the upper 

 profile very slightly concave; base of the pectoral fin below the 

 hinder part of the eye. Dorsal spine straight, four-edged, each 

 edge wdth a series of barbs, the anterior barbs being stronger than 

 the posterior ; the spine is inserted above the middle of the orbit, 

 and not more than one-half of the length of the head. Caudal fin 

 rounded; dorsal and anal fins low. Ventral spine very short, fixed. 

 Uniform brownish, or with small brown spots. 



Southern Australia. 



a-h. Adult male and female (10 inches long). George Town. Pre- 

 sented by K. Gunu, Esq. 



c. Half-grown. Melbourne. From Mr. Krefft's Collection. 



d. Adult male : skin. Australia. Purchased of Mr. Cuming. 



Balistes scaher (Forst.), Bl. Schn. p. 477, from Queen Charlotte's 

 Sound, New Zealand, appears to be allied to this species ; but the 

 manuscript drawing made by Forster represents the dorsal spine as 

 much more slender, without strong anterior barbs, which are most 

 characteristic oi M. peronii. The outline of the snout of B. scaler 

 is concave. 



32. Mouacanthus brownii. 



Aleuteiius ? browuii, Hichard.^. Voi/. Ercb. cV Ten'. Fish. p. 68. 



? Monacanthus lineo-guttatus, Hollard, Ann. Sc. Xat. 1854, ii. 

 p. 352. 



D. 32-33. A. 30-31. 



