252 PERCY SLADEN TRUST EXPEDITION. 
167. Balistes viridescens, Bl. Schn. 
Maldives. 
168. Monacanthus oculatus, Gthr. 
Maldives, 8. Nilandu, 30 fathoms. 
169. DWlonacanthus nematophorus, Gthr. 
Maldives, Suvadiva, 43 fathoms, and Mulaku, 27 fathoms; Seychelles Group, 
Amirante, 30 fathoms; Cargados Carajos, 20 to 30 fathoms. 
170. Monacanthus oblongus, Schleg. 
Seychelles Group, Amirante, 30 fathoms; Cargados Carajos, 20 to 30 fathoms. 
171. Monacanthus melanistius, sp.n. (Plate 31. fig. 4.) 
Depth of body about 2} in the length, length of head 38. Snout produced, with 
concave upper profile; upper angle of gill-opening nearly in the vertical from posterior 
edge of eye. Scales papilliform. Dorsal spine 4-sided, with 4 series of barbs, inserted 
over the middle of eye, when depressed reaching the origin of the second dorsal fin, which 
has 33 or 34 rays, the middle of which are the longest, nearly 2 as long as the spine. 
Anal 30-32. Caudal rounded. Ventral spine immovable. Body with small scattered 
round dark spots; membrane of spinous dorsal blackish; caudal with irregular dusky 
bars. . 
Plankton, surface, near Farquhar Atoll. 
Three specimens, the largest 60 mm. in total length. 
Allied to the Australian JZ. peronii, Holland. 
172. Monacanthus setifer, Benn. 
Seychelles, 37 fathoms. 
173. Pseudaluteres nasicornis, Schleg. 
Maldives, Suvadiva, 37 fathonis; Seychelles Group, Amirante, 30 fathoms. 
Ostraciontide. 
174. Ostracion cornutus, L. 
Cargados Carajos, 20 to 30 fathoms. 
175. Ostracion concatenatus, Bl. 
Seychelles Group, Amirante, 30 fathoms; Cargados Carajos, 20 to 30 fathoms. 
176. Ostracion fornasini, Bianci. 
Seychelles Group, Amirante, 30 fathoms; Cargados Carajos, 20 to 30 fathoms. 
