262 



Fam. 4. GERRID^ 



Body compressed, elevated or oblong, covered with sparoid scales. 

 Lateral line continuous. Dorsal fin with the spinous and soft 

 portions equally developed, and with a scaly sheath along the base, 

 which is separated by a groove from the other scales. Anal with 

 three (two) spines and with the soft portion similar to the soft dorsal. 

 Ventral fins thoracic, with one spine and five soft rays. Teeth small, 

 palate toothless. The lower pharyngeal bones are firmly united by 

 a suture. Branchiostegals six ; gills four, pseudobranchife present, 

 glandular ; air-bladder present. Stomach without caecal sac ; pyloric 

 appendages rudimentary. Oviparous. Vertebrae 10/14. 



Tropical seas. 



Since Kner's discovery of the Pharyngognathian nature of the 

 genus Gerres, it has become necessaiy to remove it from the family 

 Pristipomatklce, to which we formerly referred it, and place it among 

 the Acanthopterous Pharyngognaths, if such a suborder is retained 

 in the system. It must here form a separate family ; and its posi- 

 tion near the Emhiotocidte appears to be by no means an unnatural 

 one, both having the scaly sheath along the base of the dorsal. 



The family contains one genus only, of which an account has been 

 given in the first vohime ; but having since received specimens of 

 several species, the diagnoses of most of them have been revised. 



1. GERRES*. 



Gerres, Cuv. Regne Anim. ; Cue. l^ Veil. vi. p. 446. 

 Catochsenum, Cant. Catal. p. 55. 



Gerres, Diapterus, et Synistius, Gill, Proc. Acad. Nat. Sc. Philad. 1862, 

 p. 238. 



Form of the body compressed, oblong or elevated. Mouth very 

 protractile, and descending when thrust out. Eye rather large. Prte- 

 operculum generally entire. Six branchiostegals. No canine teeth. 

 Formula of the fins : Dorsal— 3j^. Anal --^. Caudal forked. Scales 

 moderate, minutely or not ciliated. Air-bladder simple ; pyloric 

 appendages in small number. Pseudobranchiae. 



AU the tropical seas, entering fresh waters. One species fi-om the 

 coast of North America. 



* 1. Gerres bilobus, Cuv. S( Val. vi. p. 466. — Cape Verde. 



2. peruvianus, Ctiv. Hf Val. vi. p. 467 ; Less. Voy. Coqu. Zool. Poiss. 



p. 180.— Coast of Peru. 



3. ricliii, Cuv. 8( Val. vi. p. 469.— East Indies? 



4. Smaris lineatus, Humboldt, Observ. Zool. p. 185. pi. 46. f. 1 ; Agass. in 



Spix, Pise. Brasil. p. 115. pi. 67. — Gerres lineatus, C%w. Sc VaK vi. p. 470. 

 — Acapulco. 



5. lucidus, Chv. cf Val. vi. p. 477. — Pondicherry. 



6. waigiensis, Qttoi/ 8f Gaim. Voy. Frei/c. Zool. p. 292. — Waigiou. 



