%9ll^'] PROCEEDINGS OF THE NATIONAL MUSEUM. 459 



V"I. — On tue NoN-AoTiN()PTEiiY(nAN Teleostomi. 



Material is not at i)resent accessible in the United States from which 

 to learn the structure of the median tins in tlic Iloloptychiida' and 

 OsteoIei)i(lida'. In drawing' up my synoi)sis of the Families of the 

 Vertebrata, in 1889*, I assumed tiiat these fins had the primitive 

 structure, such as is found in the oldest members of the Teleostomi 

 (Tarassii(la'), Dijinoi, and other subclasses, viz, that tiie axonosts are 

 equal in number to, and continuous with, the neural spines of the Ver- 

 tebrata. Tliis definition threw the families in (luestion into the Cross- 

 opterygia as distinguished from the Khipidopterygia. In the latter the 

 axonosts are much reduced in number, so that one or two fused into a 

 single piece supports each dorsal and anal lin. 



Professor Tracpiair has, however, stated that the dorsal lliisofthe 

 Osfcoh'pidie are of the Khipidopterygian type, and Mr. A. Smith 

 Woodward, in vol. ii of the Catalogue of Fossil Fishes in the British 

 Museum, t confirms this statement, and shows that the Iloloptychiida- 

 agree with them in this respect, lie does not adopt the super- 

 order Kiiipidopterygia, but combines it with the Crossoi)terygia, and 

 he places tiie families mentioned, together with the Khizodontida', 

 wiiieii is my Tristichopterida', in the order to which I referred the lat- 

 ter, the Ivhipidistia. As regards this original reference, it is clearly 

 7M'cessary on the evidence brought forward by Traquair and by Wood- 

 ward. I do not see, however, that the lihipidopterygia can be properly 

 combined with the Crossoj)terygia, since the structure of the median 

 fins is radically different, and one which offers as good ground for 

 supcrordinal distinction as do the ])aired fins offer ground for the sei)- 

 aration of theActinoi>terygia. The Tarassiidic and the Polypterida; 

 possess the; (;hara(;ters of the median fins which 1 viewed as character- 

 istic of the Crossopterygia, while the paired fins, so far as can be dis- 

 covered-from thedescriidionsof the former,^ indicate two distinct orders 

 within it. 



With this new information in our possession, it ap])ears to me that 

 the, relations of these fishes are best exi)ressed in the following way : 



There are four superorders of the Teleostomi, or true fishes, which 

 differ in the structure of the tins : 



I. Modian I'ms oach with a siiij;!*; bono n-pn-sont iuj; axonosts. 



Pair.'d liiis niiihasal liliipidujiliryyia 



II. Mi'dian liii.s \\illi luiuifioiis axoiiost.s. 



Pairtil (ins with haseosts ; pectorals with axonosts, whicli ar(> distinct from 



•>:iN<'"sts Crossojilernfiia 



Paired (ins with V)ascost8; pectoral (ins with axonosts and baseosls con- 



fonnded ; piuribasal I'odopterngia 



Pectoral (ins only with baseosta, these coufonuded with axonosts and piiui- 

 hasal iclinoptcrtjgia 



* Anicrie,an Naturalist, ji. S.')(;. f Sniilh Woodward, J. <■. ii., p. :n7. 



t L. c, IHid, p. A-n. 



t 



