Fishes of the Western North Atlantic 9 1 



and gars (Fig. 3). The body scales, lacking in only a few,'" are thin and overlap each 

 other in most instances, but in some they are thick and bony; the exposed surface 

 is smooth or only finely striate except in a few where it is either granular and sculptured 

 with a network of low ridges" or has fine'- or coarse'^ prickles; in most the exposed 

 edges are even, or nearly so, but in a few'* they are pectinate; the exposed portion of 

 the scale is not enamel-like in any living family.'^ 



A lateral line is either present or absent, as are luminescent organs. 



The swim bladder, if present, is dorsad in position'" and is either closed or con- 

 nected to the anterior part of the alimentary tract by an open duct; it is not con- 

 nected to the inner ear by a chain of bonelets (Weberian ossicles). The oviducal 

 tracts along which the ova pass to the exterior consist either of closed tubes (oviducts 

 complete) or of membranous channels that are open above but are enclosed by lon- 

 gitudinal folds of the peritoneum (oviducts incomplete).^' The inner wall of the in- 

 testine in a few has a series of circular ridge-like thickenings which suggest the spiral 

 valve of elasmobranchs, chimaeroids, and polypteroids; however, they are probably not 

 homologous (Cohen, 10: 96). 



The last few vertebrae are turned upward in a few (Salmonidae). If present, the 

 lateral processes (parapophyses) that bear the pleural ribs are simply set in pits in 

 the vertebral centra in some but are fused with the centra in others. 



Nomenclature. The names Isospondyli'^ and Malacopterygii" have been used inter- 

 changeably as ordinal names by various authors for nearly a century. More recently 

 the name Clupeiformes, proposed for this Order by Berg (^: 216, 417), has been ac- 

 cepted by Bertin and Arambourg, but in this series of publications the name Isospondyli 

 is preferred, following Cope (jj: 454, 455). 



10. Among the Alepocephalidae, Stomiatoidea, and Galaxiidae. 



ir. Among freshwater osteoglossids of South America, Malaya, and Australia. 



12. In at least two species of Argentina (see Smitt, ^o\ fig. 229). 



13. In the genus Gonorhynchus of the warm-temperate Indian Ocean and western Pacific. For an excellent illustra- 

 tion, see Cuvier and Valenciennes (jj: pi. 568). 



14. In the genus Bre-voortia, p. 342. 



15. The exposed surface of the scales was covered with an enamel-like substance (ganoine) in the fossil family Lep- 

 tolepidae, which was abundantly represented from the Upper Triassic to the Middle Cretaceous, and in the 

 Pholidophoridae of the Jurassic. 



16. The ventral "sole" of Opisihoproctus, interpreted by Trewavas as a swim bladder (5J: 610), appears to be part 

 of a light organ (Bertelsen, 5: 862). 



17. The original idea (Rathke, J7) "that the salmonoids have no oviducts and that the ova are deposited free in 

 the abdominal cavity has been handed down to the present day in all literature pertaining to the subject" 

 (Kendall, 24: 190). Similarly, according to Cuvier, the ovaries in Argentina discharge the eggs into the abdom- 

 inal cavity "comme dans les autres Salmonoides" [14: 410). Trewavas could trace no oviduct in a specimen of 

 Opisthoproctus cleared in glycerine and caustic potash before dissection (5J: 610, 611), nor could Beebe do so 

 in a mature female of Dolichopteryx [2: 78). It has been reported similarly that the ova are discharged into the body 

 cavity in the Galaxiidae, the Haplochitontidae, the Hyodontidae, and the Notopteridae. However, Kendall 

 showed from his own dissections that the actual situation, in both the Salmonidae and the Osmeridae, is as 

 summarized in the text above, and that the ova cannot be extruded if they be displaced in the abdominal cavity. 

 Probably this is equally true of the other bony fishes that have been reported as lacking oviducts. 



18. Proposed in 1871 by Cope (zz: 454-455). 



19. First proposed in 1738 by Artedi (/: i), it was given its first post-Linnaean definition in 1893 by Gill (77: 130- 

 131), as was Cuvier 's "Malacopterygiens abdominaux" {12: 159), which also included the Ostariophysi. Mala- 

 copterygii was adopted by Boulenger in 1904 (7: 543). 



