THE FAMILIES OF SYNENTOGNATHOUS FISHES AND 

 THEIR NOiVIENCLATURE. 



By Theodore Gill, LL.-D. 



In 1872 I recognized two families of Syuentognathous fishes and 

 designated them as Belouidiie and Scorn beresocidie, establishing the 

 former for Belone as generally understood/ and restricting the latter to 

 the Exocffitme, Ilemirhamphine and Scoinberesocine types.* 



The constituents were thns indicated, but the families themselves 

 were not defined. To complete this delayed task, as well as to present 

 the opinion of others, is the object of the present communication. 



I. 



The genus Eso.r was adopted by Linnreus from Artedi, and its cardi- 

 nal character was the backward position of the dorsal and anal fins, 

 and tlieir opposition to each other. The other points noted were second- 

 ary and sometimes ignored in practice. The artificial character of the 

 genus will be evident from a consideration of the species referred to it 

 in the last edition of the Systema Natura'.'' 



Species of the Linnaian genus Esox. 



* The Esox hepsetus of Linnseus was a compound of very dissimilar forms. In the tenth edition of 

 the Systema Niitiirre its synonyms are (1) the "Argentina pinna dorsali pinnre ani opposita" of the 

 Anifenitates Academicif (1, p. 321, 17-19), and (2) the I'iqnitinga of Slarcgrave. The former i.s unrecog- 

 nizable, but Cuvier and Valenciennes felt sure that it was not a Ueiiiirhaiiiphus. It had numerous 

 teeth (OS interne denticulis exasperatum), the lower jaw slightest produced (maxiila inferior paullo 

 longior), a double lateral line (duplici linea longitudinali a lateribus distinctnm), and the rays: 15. 

 approximately 10 (cerciter decern), D. 14, P. 12, V. 6, A. 15, C. 14. 



tTho Esox gymnocephalus is anotherof the undeterminable species of Linn.Tus. (,'uvier and Valen- 

 ciennes thouglit tliat It might have been an EryUirinus, but such could, not have been the case, as the 

 radial formula (I). 13, V. 10, V. 7, A. 26, C. 19) clearly shows, even assuming that Linnanishad erredas to 

 its habitat ("in India"). It essentially agrees with th& Chirocentius dcnt?x, and was ijuite likely a 

 young specimen of that species (" Maguitudme Ammodytis erat qui nobis visus"). 



' Giinther, Cat. Fish. Brit. :Mits., VI, pp. 234-256. 



'- Giinther, op. cit., pp. 256-298. ' Vol. 1, p p. 515-517. 



Proceedings of the United States National Museum, Vol. XVIII— No. lOJl. 



167 



