PISCES. 315 



shreds, extending beyond their tips, and giving 

 them a bifid appearance: lips fleshy : pharyn- 

 geans three in number; two above and one 

 below; all armed with strong teeth. 



33. LABRUS __ Lips double: branchiostegous mem- 

 brane with from four to six rays : maxillary teeth conical ; 

 the anterior ones longest : pharyngeans cylindrical, blunt, 

 forming a pavement. 



(1. LABRUS.) Preopercle with the margin entire: cheeks and opercle 

 scaly : first dorsal spines not elongated. 



First dorsal spines produced into long flexible threads. 



(2. JULIS.) First dorsal spines elongated : head entirely smooth, and 

 without scales. 



(3. CRENILABRUS.) Preopercle with the margin denticulated: cheeks 

 and opercle scaly. 



XII. CENTRISCID^E. Mouth at the extremity 

 of a long tube, formed by a prolongation of 

 the rostral and opercular bones. 



34. CENTRISCUS. Body oblong-oval, compressed at 

 the sides, carinated beneath : mouth extremely small, cleft 

 obliquely : branchiostegous membrane with two or three 

 slender rays : two dorsals ; the anterior one placed very 

 backward, with the first spine much longer and stouter 

 than the others: ventrals small, behind the pectorals. 



ORDER II. MALACOPTERYGII. 



All the fin-rays, with the exception sometimes of the 

 first in the dorsal and the first in the pectorals, 

 soft and cartilaginous ; these rays of an articulated 

 structure, and generally more or less branched at 

 their extremities. 



