ICHTHYOLOGY. 217 



C. coMPEESSus, Day. 



B. vii.; D. %-^^s^; P. 21; V. }; A. 1t^^^\ C. 21. 



Lower jaw the longer. Teeth villiform in both jaws, and on vomer, palate, and 

 tongue. Lateral line a very gradual curve. The keeled scales are most developed 

 on the free portion of the tail, where the largest equal -^V of height of body, and 

 are 13 in number. Colour silvery, with a minute opercular spot. Vertical margin 

 of preopercle dark. 



The Andanians. 



C. oBLOKGUs, Cuv. ct Val. 

 Ro-thul-dah. Andamaus. 



E. vii.; D. 8 -i^^\ P. 21 ; V. \; A. 2 rr^nr ; C. 18. 



Lower jaw thc^ longer. Teeth in a narrow villilbrm band in tlie upper jaw or 

 in two rows, with the outer slightly enlarged. In the lower in a single row, except 

 in front, where they are largest, and have a few villiform teeth behind them. Teeth 

 also on vomer, palatines, and tongue. Keeled scales over the whole of the straight 

 portion of the lateral line, the largest equal -iV of the height of the body, 34 to 40 in 

 number. Colour of adults olive above, white below. Fins yellow. Caudal orange, 

 with its terminal half black, but white-tipped. 



The Andaraans. 



C. AEM.vTus, Forsk. 



B. vii.; D. 6-8 -^^^f, P. 21 ; V. 1; A. 2 tit Vr I C. 19. 



Lower jaw the longer. Teeth villiform in both jaws, with an outer somewhat 

 enlarged row on the premaxillaries ; they are also present on the vomer, palatines and 

 tongue. Lateral line makes a low curve and .straightens below the centre of the 

 second dorsal. Keeled plates commence in tlie last half of the straight portion, but 

 are small and 20 in number. Colour, top of head and back bluish-green, sides of the 

 head and body golden with purple reflexions. A spot on the opercle. First dorsal 

 black, .second and anal yellowish, with dark edges. The young vertically banded. 



The Audamans. 



B. No teeth on the palate. No fenlets. 



C. NIGEnTNNIS. 



B. vii.; D. 7-8 ^irHr; P. 23; V. i; A. 2 -„-Ht-; C. 19. 



Lower jaw somewhat the longer. Teeth in both jaws of equal size in a single 

 row. A few im the tongue, but none on vomer or palatines. Lateral line straightens 

 behind the fourth dorsal ray. The largest scales on it equal -iV the height (jf the 

 body and they number 55 to 60. Colour .silvery, shot with gold. First dorsal l)Iack. 

 Anal white-edged. A dark band along the second dorsal, with its upper anterior 

 corner white. 



The Andamans. 



CnoEiNEJTDS, Cmier et Valencieimen. 



Branchiostegals 7 or 8. Pscudobranchiae. Teeth in jaws, vomer, palatines, and 

 tongue. Two dorsal fins, with an immovable lu-ocumbcnt spine in front. First 

 dorsal composed of a few free spines. Posteiior dorsal and anal rays detached or 

 nearly so. Dorsal scales mostly lanceolate. Air-vessel bifurcate posteriorly. 



0. TOLTJ, Russell. 



B. viii.; D. 7T»^ira; P. 20; V. A; A. 2 ^^rh:!^; C. 19. 



Teeth comparatively large, in a single in the upper jaw and in two rows in the 

 lower, the outer one directed somewhat outwards, and a pair of canine-like teeth on 

 either side of the mandibular symphysis. The last 8 or 10 rays of both solt dorsal 

 and caudal, semidetached. Colour of back greenish, .shot with blue. Belly silvery. 

 Six or eight indistinct vertical spots along the lateral line. Grows to eighteen inches. 



The Andamans. 



