BOW-FINS. 



79 



bubbles of gas from the nostrils, situated uear the end of the 

 snout, in a manner suggesting that the air-bladder assists in the 

 respiration. 



Amiiformes (Bow-fins). 



The Amiiformes or Protospondyli form a suborder of fishes 

 all of which, except Amia, the Bow-fin of North America, are 

 extinct, and most of which are Mesozoic in their stratigraphical 

 range. The dermal fin-rays of the dorsal and anal fins are equal 

 in number to the endoskeletal supporting elements; the endo- 

 skeletal elements of the pelvic fins are rudimentary or absent ; 

 there is no infraclavicle in the pectoral girdle. The extremity of 

 the vertebral column is upturned, but the outline of the tail-fin is 

 symmetrical. There is a median jugular plate between the halves 

 of the mandible ; the branchiostegal rays are flattened and rather 

 broad ; in the mandible are splenial and coronoid bones; there 

 are two vomerine bones (coalescent in the Pycnodontidse) ; there 

 is no supraoccipital bone (except in Dapedius). The suborder 

 comprises the families Senrionotidre, M acrosemiidse, Pycnodontidse, 

 Eugnathidae, Amiidae, and Pachycormidse. 



Wall- 

 case 7. 



Fig. 46. — Lepidotus mantelli. 



The Semionotidee (fig. 46), the oldest and most generalised of 

 the Amiiformes, are represented by Lepidotus notopterus (222), 

 from the Lithographic Stone of Bavaria, the great Lepidotus 

 muximus (1037, Table 49) from the same formation and locality, 

 and a specimen of Dapedius leiosomus (223). In this family 



Lepi- 

 dotus. 



