264 CHROMIDES. 



28. Gerres oblongus. 



Cuv. 8f Vah vi. p. 479. 



The height of the body is less than one-fourth of the total length. 

 Spines of the fins slender. Silvery, with five or six indistinct 

 brownish vertical bands. Lateral line nearly straight. {Cuv.) 



Sea of Ceylon. 



Fam. 5. CHROMIDES. 



Chromides, Miill. Berl. Abhandl. 1844, p. 169 ; Owen, Led. Comp. 

 Anat. ii. p. 48. 



Body elevated, oblong or elongate, scaly, the scales generally being 

 ctenoid. Lateral line interrupted or subinterrupted. One dorsal 

 fin, with a developed spinous portion ; three or more anal spines ; 

 the soft anal similar to the soft dorsal. Ventral fins thoracic, with 

 one spine and five soft rays. Teeth in the jaws small ; palate smooth. 

 The lower pharyngeal bone triangular, with a median suture. Bran- 

 chiostegals five or six ; gills four ; pseudobranchiae none ; air-bladder 

 present. Pj'loric appendages none (or in small number) ; stomach 

 with a csecal appendage. The abdominal and caudal vertebrae are 

 nearly equal in number, or the number of the former is slightly in- 

 creased. 



Freshwater fishes from the tropical parts of Africa and America ; 

 one genus from Western India. The species with lobate teeth and 

 with many circumvolutions of the intestines are herbivorous, the 

 others carnivorous. 



Synopsis of the Genera. 



A. The spinous and soft portions of the dorsal fin are of equal extent, or the 

 former is the more developed. 

 I. The anterior prominences of tlie outer branchial arch are short, or lanceolate 

 and widely set ; no additional lobe. 



a. Teeth lobate and anal spines numerous. 



Body elevated 1 . Etroi'lus, p. 265. 



b. Teeth lobate ; anal spines 3. 



Operculum scaly '2. Chromis, p. 267. 



Operculum scaleless 3. Sarotherodon, p. 273. 



c. Teeth conical ; scales cycloid. 



Anal spines 3 4. Hemiciiro.mis. p. 274. 



