5. MONACANTHITS. 237 



q. Adult: skin. From Grouow's Collection. 



r, s-t. Adult : skins. 



u. Adult : skeleton. Shanghai. Purchased of Mr. Jamrach. 



10. Monacanthus megalums. 



PMonacanthus bifilamentosus, Less. Voy. Coq. Poiss. p. l(Jl>, pi. 8. 

 Monacanthus megalourus, Hichards. Ic. Pise. p. 5 pi. 1. f. 3. 



chinensis, Pichai-ds. Voy. Ereb. 8f Terr. Fish. p. 64, pi. 40. figs. 



3 & 4 ; Hollar d, Ann. So. Nat. 1854, ii. p. 346. 



Closely aUied to M. chinensis, but with larger scales, more slender 

 dorsal spine, &c. 



D. 32. A. 31. 



Scales as in M. chinensis, but larger ; there are about twenty in a 

 transverse series running from the end of the dorsal fin to that of the 

 anal. A double series of caudal spines as in M. chinensis. Body 

 elevated, its depth being contained once and three-fourths in the 

 total length (without caudal) ; the upper profile rises from the dorsal 

 spine to the origin of the soft dorsal, which is the highest point on 

 the back. Snout pointed, with the upper profile concave. Dorsal 

 spine rather slender, shorter than the head, armed behind with a 

 double series of strong recurved spines, inserted above the posterior 

 half of the eye. Caudal fin rounded, as long as the head ; old males 

 with the upper caudal ray produced. Ventral spine moveable, taper- 

 ing, without spinelets, attached to the cutaneous ventral expansion, 

 which is much developed, far extending beyond the spine. Dorsal 

 and anal fins moderately elevated, the longest rays being more than 

 half as long as the head. Brownish, marbled with darker ; anal fin 

 with a networJc of blackish meshes ; caudal with one or two bluish 

 intramarginal transverse Hnes, and sometimes with blackish dots. 



Australian seas. 



a-h. Adult : skins (10 inches long). Australia. 



c. Adult : skin. Port Jackson. Purchased of Mr. Gould. 



d-e. Half- grown : skins. Freycinet's Harbour. Voyage of the 



' Herald.' 

 /. Adult. Presented by the Royal College of Surgeons. 



11. Monacanthus occidentalis. 



? Pira-aca, Marcgr. p. 154 ; Willughby, tab. J. 4. fig. 1. 

 Monacanthus tomentosus, MOM. ^- Trosch. in Schomburgk, Barhadoes 

 p. 676 ; HoUard, Ann. Sc. Nat. 1854, ii. p. 348, pi. 13. fig. 5. ' 

 ? Monacanthus piraaca, Kner, Novara, Fiscn. p. 396. 



D. 33. A. 31. 



Scales exceedingly small, without median crest, the skin having 

 a velvety appearance ; they are much larger and imbricate on the 

 abdominal flap, which is much developed, extending far beyond the 

 point of the ventral spine. On each side of the tail one or two pairs 

 of small spines in adult examples. Body elevated, its depth being 

 about two-thirds of the total length (without caudal). The profile 



