MANUAL OF NATURAL HISTORY. 91 



1. FAMILY. Chimceras (Chimseridas). Beak conical, 

 in some ending in a foliaceous appendage ; 

 one external branchial opening, with five ter- 

 minal sub-divisions ; tail long, attenuated, 

 and pointed ; dorsals contiguous or remote ; 

 jaws furnished with hard plates instead of 

 teeth. 



III. ORDER -^AMPHIBIAN-FISHES (Protopteri). 



Endo-skeleton partly osseous, partly cartilaginous ; 

 exo-skeleton as cycloid scales ; pectorals and ven- 

 trals as flexible filaments ; gills filamentary, free, 

 swimming-bladder as a double lung, with an air- 

 duct. 



1. FAMILY. Lepidosirens (Lepidosirenidse). Body 

 lengthened, or long, covered with scales ; sur- 

 face of body spotted; gill-filaments, in some, 

 tripinnatifid ; ribs 36 to 55 pairs. Inhabit 

 marshy spots. Some remain torpid under 

 ground during dry season. 



Obs. The position of this singular creature in the animal 

 kingdom has been keenly debated. It possesses in nearly 

 equal proportion characters of an Amphibian and of a 

 Fish, and it has accordingly been arranged by different 

 authorities in one or other of these two classes. The 

 former are held to predominate by Milne - Edwards, 

 Bischoff, and Gray, while by Owen and by Muller the 

 latter are believed to deserve the preference. In accord- 

 ance with the views of these last, and until further enqui- 

 ries finally decide the matter, it has been deemed advisable 

 to continue it among the fishes. Its ichthyic claims have 

 been favoured by Owen upon the " accumulative evideace of 



