692 PLECTOGNATHI. 



B. vi, D. 3/25-26, P. 14, A. 22, C. 12, L. 1. 40, L. tr. 23-26. 



Length of head 3|, of caudal fin 61, height of body 2^ in the total length. Eyes— high up and not 

 above 1/2 a diameter from posterior end of head, H diameters apart. No groove in front of eye. Fins — 

 second dorsal and anal fins rather low, the corners rounded. Ventral spine movable. Posterior edge of 

 caudal fin convex or undulated. Scales — cheeks entirely scaly : a patch of a few enlarged^ scutes behind the 

 gill-opening : 4 to 6 strong spines on either side of the tail in two rows. Oolowrs — brownish, with numerous 

 undulating yellow lines from the eye and back to the anal and caudal fins : three or four likewise pass from the 

 angle of the mouth and lips to between the ventral and anal fins : a dark band along the base of the second 

 dorsal and anal : and a black margin to interspinous membrane between first and second dorsal spines. In 

 some examples a black blotch exists at the side of the tail near the base of the candal fin. 



Habitat— UeA Sea, East coast of Africa, seas of India to the Malay Archipelago, and beyond. The 

 example figured (a skin 10 inches in length) was from the Andamans. 



13. Balistes erythrodon, Plate CLXXY, fig. 4. 



Bolide noir, Lacep. i, pp. 378, 380, t. xv, f. 2. 



Xenodon niger, Riipp. N. W. Fische, p. 53, t. xiv, f. 3 ; Sleeker, Balistes, p. 37 (not Mungo Park). 



Erythrodon niger, Eiipp. Verz. Fisch. Senck. Mus. p. 34 ; Bleeker, Atl. Ich. v, p. 106, t. ccxix. 



Zenodon niger, Swainson, Pishes, ii, p. 326. 



Pyrodon niger, Kaup, Sclerod. p. 222 ; Bleeker, En. Pise. p. 193. 



Balistes niger, HoUard, Ann. Sc. Nat. 1864, i, p. 315. 



Balistes erythrodon, Giinther, Catal. viii, p. 228 ; Klunz. Fisch. Hoth. Meer. 1871, p. 631. 



B. vi, D. 3/35, P. 14, A. 30, C. 12, L. 1. 33-36, L. tr. 17. 



Length of head 4^, of caudal fin 3f, height of body 3 in the total length. Eyes — 3 diameters from end 

 of snout and 1| apart. A shallow scaly groove in front of eye. Lower jaw projecting. Teeth — reddish-brown, 

 strongly compressed, notched: the tooth on the side of the central pair in the upper jaw considerably 

 projecting. Fins — first dorsal commences above the gUl-opening, its spine strong and about 1/2 as long as the 

 head. Ventral spines movable. Caudal deeply concave, with its outer rays prolonged. Second dorsal and 

 anal elevated, especially anteriorly. Scales — cheeks entirely scaly : some enlarged scutes behind the gill-opening. 

 Scales roughened, those along the middle of the body and tail with a small elevated tubercle on each, but no 

 prominent spines. Colours— oi a deep brown, a black stripe after encircling the mouth goes to the base of the 

 jDectoral fin. Vertical fins nearly black, the caudal with a white posterior edge. 



Habitat. — Red Sea, East coast of Africa, seas of India to the Malay Archipelago. The example figured 

 (life-size) was from Mangalore, where it was procured by Dr. Dobson. 



Genus, 3 — Monacanthus, Cuvier. 



AhdariMS, Cuv. : Stephanolepis, Gill : Ohcetodermis, Paramonaeanthus, Amanses, Gray : Pseudomona- 

 canthus, Liomonacamthus, Oxymonacanthus, Branchaluteres, Aoamthaluteres, Gerataeanthus, Paraluteres, Pseiida- 

 hderes and Aluteres, Bleeker. 



Body compressed. Barbels abieni. Incisoriform teeth in both jaws, in two rows in the upper with six in 

 the outer row, and a single row of six in the mandibles. The first dorsal fin composed of a spine which may be 

 feeble or strong and merely rough, or provided posteriorly or laterally with barbs, occasionally a second rudimentary 

 one: ventral fin, when present, reduced to a single osseous process, sometimes rudimentary and either movable or 

 fixed. Scales minute and rough : cutaneous filaments present in some species : the side of the tail may be peculiarly 

 armed in adult males, hut less apparently so or not at all in the females. Vertebrae 7/11-14. 



SYNOPSIS OP INDIAN SPECIES. 



A. — Dorsal spine with only 2 rows of barbs, pointing backwards and downwards. 



1. Monacanthus setifer, D. 1/28-34, A. 29-33. Second dorsal fin with its first ray prolonged. Brownish, 

 marbled and streaked with darker. Indian and Atlantic Oceans. 



2. Monacanthus choir ocephahbs, D. 1/28, A. 28-30. Fleshy tentacles over Ijody. Seas of India to the 

 Malay Archipelago. 



B. — Dorsal spine rough but barbless. 



3. Monacanthus monoceros, D. 1/46-48, A. 48-53. Snout moderately produced, with its upper profile 

 convex. Indian Ocean and Atlantic portions of tropical America. 



4. Monacanthnis scriptus, D. 1/44-48, A. 47-52. Snout produced with its upper profile concave. Indian 

 Ocean. 



A. — Dorsal spine with only 2 rows of barbs, pointing backwards and downwards. 



1. Monacanthus setifer. 



Bennett, Proc. Zool. Soc. 1831, p. 112: Bollard, Ann. Sc. Nat, 1854, ii, p, 342, pi. xii. f . 4 ; Dekay, 

 New York Fauna, Fish. p. 337, pi. lix, f. 194 ; Giinther, Catal. viii, p. 239. 



