230 SCLBRODERMI. 



On the anatomy, see Hollard, Ann. Sc. Nat. 1853, xx. p. 71 et seq., 

 pi. 2. 



The species can be arranged thus : — 



I. Anal Jin with less than 40 rai/s (24-36) ; ventral spine present or 

 absent : Monacanthiis, m. 



A. Dorsal spine withcnt barbs. 



1. Ventral spine present, anchylosed to the pelvic bone {Liomona- 



canthus, Amanses, et Oxyinonacantluis, Bllir.), p. 230. 



2. Ventral spine present, moveable (^Paramonacanthtis, sp., Blkr.), 



p. 233. 



3. Ventral spine none (Parahderes et Brachalideres, Blkr.), p. 234. 



B. Dorsal epine with only two series of barbs. 



1. The barbs point backwards and downwards. 



a. Ventral spine present, moveable ; the cutaneous ventral expan- 



sion much developed, extending beyond the spine (Monacan- 

 thus, sp., Blkr.), p. 236. 



b. Ventral spine present, moveable ; the cutaneous ventral expan- 



sion moderately developed, not extending beyond the spine 

 (Mmiacanthus, sp., et Paramonacanthns, sp., Blkr.), p. 238. 



c. Ventral spine present, anchylosed to the pelvic bone, p. 243. 



2. The barbs are lateral, pointing outwards and downwards, p. 244. 



C. Dorsal spine with irregularly arranged barbs and filaments {Cha- 



todermis, Blkr.), p. 245. 



D. Dorsal' spine with four series of barbs. 



1. The front series are much closer together than the hinder series, 

 and formed by femall barbs {PseudoynonacantMts, sp., Blkr.), p. 246. 



2- The dorsal spine is four-edged, the edges being equidistant and 

 armed with barbs {Pseudomonacanthus, sp., et Acanthahderes, 

 Blkr.), p. 249. 



[I. Anal Jin with 40 (39) or more rays. Ventral spine none : Aluteres, m. 



A. Dorsal spine above the orbit. 



1. Dorsal spine with distinct barbs, p. 251. 



2. Dorsal spine feeble, rough, but without barbs (Ceratacanthus et 



Aluteres, GiU & Blkr.), p. 251. 



B. Dorsal spine in advance of the orbit {Psetidaltderes, Blkr.), p. 254. 



I. Anal Jin with less than 40 rays (24-36). Ventral spine present or 

 absent : Monacanthus. 



A. Dorsal spine tvithoid barbs. 



1. Ventral spine present, anchylosed to the pelvic bone. 



1. Monacanthus pardalis. 



Synonymy of Indian specimens. 

 Grynzert, HauU. i. p. 462, tab. 09. fig. 1. 



PBalistes sandwichiensis, Qiioy i^- Gaim. Voy. Uran. Zool. p. 214. 

 Monacanthus pardalis, Riij}}). N. W: Fisch. (1855) p. 67, taf. 16. 

 fig. 3i HMard, Ann. Sc. Nat. 1854, ii. p. 328. 



