MANUAL OF NATURAL HISTORY. 99 



21. Family. — Spine-Backs (Notocanthidse). Body 



anguilliform, much compressed ; dorsal and 

 anal, when present, very long, and close to 

 caudal which is small ; series of free, detached 

 spines before dorsal ; snout produced. 



22. Family. — Scale-less Mackarels (Alepisauridae). 



Body lengthened, linear, much compressed ; 

 head lengthened, pointed ; teeth large, un- 

 equal, very acute ; mouth wide ; two dorsals, 

 the hinder adipose ; scales none. 



23. Family. — Sword-Fishes (Xiphiidae). Upper jaw 



excessively prolonged, considerably flattened 

 above, the edges sharp ; mouth beneath ; ven- 

 trals either wanting, or a single inflexible 

 bone in each. 



24. FAMILY. — Mackarels (Scomberidae). Body ob- 



long, lengthened, smooth, covered with very 

 small scales ; caudal fin deeply forked, large; 

 tail often bearing spurious finlets ; no fleshy 

 lips ; dorsals two, in some close together. 



25. Family. — Climbing-Fishes (Anabatidae). Body 



ovate, sub-fusiform, or cylindrical ; dorsal fin 

 single, mostly with spinous rays ; upper pha- 

 ryngeals of branchia divided into numerous 

 small, irregular lamellae, forming small cells, 

 in which they have the power of retaining 

 water, for moistening the gills when the ani- 

 mal is on shore ; dorsal single ; ventral gene- 

 rally extremely long, narrow, and ending in 

 a filament. 

 The members of this family are remarkable for 



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