PISCES. 311 



15. XIPHIAS. Lateral line unarmed : a single dorsal, 

 continuous : body elongated ; the snout produced into a 

 sword-like process : jaws without teeth : sides of the tail 

 with a strong projecting keel : ventrals wanting. 



16. CENTRONOTUS __ Lateral line unarmed : spines 

 of the first dorsal free, and not connected by a membrane : 

 ventrals always present. 



(1. NAUCRATES.) Body fusiform: sides of the tail keeled: two free 

 spines before the anal. 



Body compressed: sides of the tail not keeled: two free 

 spines before the anal : before the spines on the back, a reclined spine 

 directed forwards. 



17- CARANX. Lateral line armed with large, im- 

 bricated, spinous plates: two distinct dorsals; before the 

 first a sharp reclined spine directed forwards : some free 

 spines before the anal; sometimes connected, forming a 

 small fin: body fusiform. 



18. ZEUS -- One dorsal; the spinous and soft por- 

 tions separated by a deep notch : body oval, compressed : 

 mouth very protractile : teeth small, few in number : 

 ventrals thoracic. 



(1. ZEUS.) Dorsal spines accompanied hy filamentous prolongations 

 of the membrane : a series of forked spines along the base of 

 the dorsal and anal. 



(2. CAPROS.) No spines at the base of the dorsal and anal fins: 

 body covered with rough scales. 



19- LAMPRIS -- Dorsal entire, very much elevated 

 anteriorly : anal also elevated, with one small spine in 

 front of the base : body oval, compressed : no teeth : 

 ventrals, and lobes of the caudal, very much elongated; 

 the former abdominal, with ten rays : sides of the tail 

 keeled. 



20. CORYPKLENA. _ Body compressed, elongated: 

 upper part of the head presenting a sharp edge : one 

 dorsal running the whole length of the back; all the 



