PISCES. 309 



shield-like plates : several free spines instead of a first 

 dorsal : ventrals reduced nearly to a single spine : branch- 

 iostegous membrane with three rays : teeth in both jaws ; 

 none on the vomer or palatines. 



(1. GASTEROSTEUS.) Bones of the pelvis united, forming a trian- 

 gular plate on the abdomen : ventrals with only one soft ray. 



(2. SPINACHIA.) Bones of the pelvis separate: ventrals with two 

 soft rays: lateral line armed with large carinated scales. 



III. SCI^ENID^E.. Preopercle denticulated; opercle 



with spines: mouth but little protractile: no 



teeth on the vomer or palatines : bones of the 



face and cranium often cavernous, causing the 



snout to appear more or less protuberant. 



9. SCI^ENA. Head protuberant, covered entirely, as 

 well as the body, with scales : two dorsals ; the second 

 much longer than the first : anal short : preopercle, 

 except in advanced age, denticulated ; opercle terminating 

 behind in two flat spines : branchiostegous membrane with 

 seven rays. 



(1. SCLENA.) A row of strong pointed teeth in each jaw, accom- 

 panied, in the upper, by smaller ones behind : anal with only one 

 small spine : no cirrus on the chin. 



A broad band of fine small teeth in each jaw without an 

 anterior row of stronger ones : anal with two spines, the second strong : 

 a barbule beneath the symphysis of the lower jaw. 



IV. SPARID^E. No denticulations on the pre- 

 opercle, or spines on the opercle : palate without 

 teeth : mouth not protractile : body oval, covered 

 with large scales; no scales on the vertical 

 fins. 



10. SPARUS __ Sides of the jaws furnished with 

 rounded molars forming a pavement : cheeks scaly : a 

 single dorsal : branchiostegous membrane with five or 

 six rays. 



