312 PISCES. 



rays nearly equally flexible, but the anterior ones not 

 articulated : branchiostegous membrane with seven rays. 



(1. CENTROLOPHUS.) Head oblong: palate destitute of teeth: a 

 space without rays between the occiput and commencement 

 of the dorsal. 



VII. T^ENIOIDEI. Body venj much elongated, as 



well as compressed: scales small. 



* Snout elongated: gape wide: teeth strong, sharp, and 

 cutting : lower jaw projecting. 



21. LEPIDOPUS. Ventrals reduced to two small 

 scales : dorsal extending throughout the whole length : 

 anal narrow : caudal well formed : branchiostegous mem- 

 brane with eight rays. 



22. TRICHIURUS. Ventrals and caudal wanting : 



tail produced into a long, slender, compressed filament : 

 anal represented by a series of small, almost invisible, spines : 

 branchiostegous membrane with seven rays. 



** Mouth small, very protractile : teeth small. 



23. GYMNETRUS. Anal entirely wanting: dorsal 

 long ; the anterior rays prolonged : ventrals very long 

 (but easily broken) : caudal of few rays, attached vertically 

 to the extremity of the tail, which terminates in a small 

 hook or claw : branchiostegous membrane with six rays. 



*** Snout very short ; gape oblique : teeth well deve- 

 loped. 



24. CEPOLA Dorsal and anal long, both reaching to 



the base of the caudal : ventrals moderately developed : 

 branchiostegous membrane with six rays. 



VIII. MUGILID^E. Body oval, approaching to 

 cylindric; covered with large scales: snout 

 very short: mouth transverse, angular when 



