242 SCLERODERMT. 



men has the dorsal and anal fins as mnch elevated as speci- 

 men b. 

 d, e,f. Several examples, 3-4 inches long. Zanzibar. Presented 

 by Messrs. Playfair and Kirk. 



This species is subject to numerous variations of form and colour, 

 independent of locality or age. Examples of 3-4 inches in length 

 appear to be adult. 



17. Monacanthus chcerocephalus. 



Monacanthiia choirocephalus,5/ceA;. Verh. Bat. Gen. xxiv. Balist. p. 19, 



pi. 2. fig. 4. 

 Paramonacanthus choirocephalus, Bleek. Atl. Ichth. Balist. p. 131, pi. 



227. fig. 3. 



D. 28. A. 30. 



Skin finely velvety. Body rather elevated, its depth being more 

 than one-half of the total length (without caudal). Pectoral situ- 

 ated immediately behind the vertical from the orbit. Snout of 

 moderate length, with the upper profile nearly straight. Dorsal 

 spine rather strong, not much shorter than the head, armed with 

 two rows of barbs behind, situated above the hinder half of the 

 orbit. Caudal fin rounded, dorsal and anal fins low. Ventral spine 

 small, moveable, with spinelets. Brownish, with a round blackish 

 spot in the middle of the side. Caudal with two cross bands. 



East-Indian archipelago. 



a. Type of the species, 3| inches long. From Dr. Bleeker's Collec- 

 tion. ^ 



Moymcanihus nemurus, Bleek. Verh. Bat. Gen. xxiv. Balist. p. 20, 

 pi. 2. fig. 3, or Paramonacanthus nemurus, Bleek. Atl. Ichth. Bal. 

 p. 132, pi. 225. fig. 2, from Java and Singapore, is closely allied to 

 M. choirocephalus, but has the body somewhat less elevated, and the 

 upper profile of the snout a little convex (the upper caudal ray is 

 produced into a short filament). 



18. Monacanthus melanocephalus. 



Balistes monoceros, Lacep. i. pi. 17. fig. 3, c. deseript. part. 

 Monacanthus melanocephalus, Bleek. Nat. Tyds. Ned. Ind. v. p. 95 ; 

 Atl. Ichth. V. p. 127, pi. 223. fig. 1. 



janthinosoma, jyfe^'A;. Nat. Tyds. Ned. Ind. vi. p. 503. 



? Monacanthus aspricaudus, Hollard, Ann. Sc. Nat. 1854, ii. p. 330. 



D. 31-32. A. 26-28. 

 Body covered with small but very distinct scales ; each scale 

 spiny, the spinelets being larger and hooked towards the root of the 

 caudal. Body rather oblong, its depth being about one-half of the 

 total length (without caudal). Pectoral fin situated behind the ver 

 tical from the orbit. Snout of moderate length, rather pointed, with 

 the upper profile concave. Dorsal spine situated above the middle 

 of tk". orbit, strong and long, nearlv as lone as the head, armed on 



