370 MEMOIRS OF THE CARNEGIE MUSEUM 
1834. Ductor leptosomus L. Agassiz, Verhandl. Ges. Vaterland. Mus. Béhmen, 
p. 66 (namé only). 
1835.- Ductor leptosomus L. Agassiz, Neues Jahrb., p. 293 (name only). 
1834-44. Ductor leptosomus L. Agassiz, Poiss. Foss., Vol. V, pt. 1, p. 53, pl. XII. 
1876. Ductor leptosomus ¥. Bassani, Atti Soc. Veneto-Trent. Sci. Nat., Vol. III, 
p. 184. 
1901. Ductor leptosomus A. 8. Woodward, Brit. Mus. Cat. Fossil Fishes, pt. IV, 
p. 448. 
Type.—Imperfect fish; Paris Museum of Natural History. 
One large and several smaller and imperfect specimens are to be seen in the 
British Museum. The Carnegie Museum possesses a series catalogued as follows: 
4214, 4220 and 4220a, 4227 (imperfect), 4130, 4518, 4514, 5242, 5243 (juv.). 
Genus ACANTHONEMUS Agassiz. 
This genus, like the preceding, is entirely extinct, and known by a single 
species from the Upper Eocene and Upper Oligocene respectively, both exceed- 
ingly rare. 
24. Acanthonemus subaureus (Blainville). (Plate XCIV.) 
1796. Zeus gallus G. 8. Volta, Ittiolit. Veronese, p. 87, pl. XIX, fig. 3 (errore). 
1796. Chetodon aureus G. 8. Volta, ibid., p. 212, pl. LI, fig. 3 (errore). 
1818. Chetodon subaureus, H. D. de Blainville, Nouv. Dict. d’Hist. Nat., Vol. 
XXVII, p. 354. : 
1834. Acanthonemus filamentosus L. Agassiz, Poiss. Foss., Vol. V, pt. I, D. 25, 
pls.cLE. LV. 
Type.—Imperfect fish; Paris Museum of Natural History. 
The fine example shown in the accompanying plate, cataloged as No. 4439, 
is the third example known. The other two, one of which is the type, belong to 
the Paris Museum. ‘The six anterior dorsal fin-rays are greatly elongated. 
Genus Tracuynotus Lacépéde. 
To this genus, as re-defined by Cuvier from his study of recent forms, a single 
small species was somewhat doubtfully referred by Agassiz on the basis of a soli- 
tary example from the Eocene of Monte Bolea. After quoting Cuvier’s remarks on 
the near approach of this genus to Lichia and its allies, Agassiz remarks: ‘D’aprés 
cela, oncomprend qu’il doit étre plus difficile encore de déterminer les espéces 
fossiles; surtout si toutes les parties du squelette ne sont pas parfaitement con- 
