i6o 



Series Ostariophysi 



55 



bone, and, as observed by Parker, in the interclavicles. There is 

 also a superficial resemblance in the dermal bones." But it is 

 not likely that any real affinity exists. 



The sturgeons lack the characteristic 

 auditory ossicles, or "Weberian ap- 

 paratus," which the catfishes possess in 

 common with the carp family, the Cha- 

 racins, and the Gymnonoti. These orders 

 must at least have a common origin, 

 although this origin is obscure, and fossil 

 remains give little help to the solution of 

 the problem. Probably the ancestors of 

 the Ostariophysi are to be found among 

 the allies of the Osteoglossida. Gill has 

 called attention to the resemblance of 

 shoulder-girdle of the Erythrinus to Amia. In any event, all the 



Buffalo-fish. Ictiobus bu- _ . . . \. 



balus Rafinesque, show- Ostanophyst must be considered together, 



(59) \ h \fteS?aTks a ) id ES ^ * S nOt conceivable that SO Complex 



a structure as the Weberian apparatus 



should have been more than once independently evolved. 

 The branchiostegals, numerous among the Isospondyli, are 

 mostly few among the Ostariophysi. 



To the Ostariophysi belong the vast majority of the fresh- 

 water fishes of the world. Their primitive structure is shown in 



FIG. 119. Inner view of 



FIG. 120. Weberian apparatus and air-bladder of Carp. 



after Weber.) 



(From Gunther, 



many ways; among others by the large number of vertebrae 

 instead of the usual twenty -four among the more highly special- 

 ized families of fishes. We may group the Ostariophysi under 



