430 
ACTINOPTERYGII. 
Genus SEMIOPHORUS, Agassiz. 
[Poiss. Foss. vol. iv. 1838, p. 14.] 
Trunk oblong, somewhat deepened, and head relatively large, 
without prominent supraoccipital crest. Eye large; cleft of mouth 
small, the gape not extending behind the anterior border of the 
orhit; maxilla expanded behind; teeth minute or absent. Pectoral 
fins small ; pelvic fins very large and inserted in advance of the 
latter ; dorsal fin extending along the whole of the back, pressed 
forwards over the head, with a few short anterior spines, its anterior 
portion excessively elevated, its hinder portion low and fringe-like; 
anal fin much extended, low and fringe-like ; caudal fin widely 
expanded but only slightly forked. Scales thin and small, none 
enlarged, some extending over the bases of the median fins. 
Semiophorus velifer (Volta). 
1790. Kurtux velifer, G. S. Volta, Ittiolit. Veronese, p. xxvii. ph v)1, 
figs. 1, 2 ( non fig. 3). 
1818. Chee/odon velifer, II. 11. de Blainville, Nouv. Diet. d’Hist. Nat. 
vol. xxvii. p. 355. 
1835. Semiophorus velifer, L. Agassiz, Neues Jalirb. p. 301 (name 
only). 
1838-42. Semiophorus velifer, L. Agassiz, Poiss. Foss. vol. iv. pp- l^i 
219, pi. xxxvii a. 
1859. Semiophorm velifer, A. B. Massalongo, Specimen Pliotogr. Annn. 
Foss. Agr. Veron. p. 27, pi. vi. 
1876. Semiophorus velifer, F. Bassani, Atti Soc. Veneto-Trent. Sci. 
Nat. vol. iii. p. 179. 
(?) 1878. Semiophorus gigas, A. de Zigno, Mem. R. Istit. Veneto, 
vol. xx. p. 448, pi. xv. [Imperfect fish ; Zigno Collection, 
University of Padua.] 
Type. Nearly complete fish ; Museum of Natural History, Paris. 
Tho type species, attaining a length of about 0-18. Length of 
head with opercular apparatus considerably less than tho maximum 
depth, and contained three times in tho total length of the fish 
(including caudal fin). Pelvic fins when adpressed not reaching the 
caudal fin ; dorsal fin with about 5 small antorior spines and from 
50 to 55 articulated rays, the elevation of tho anterior half of the 
fin somewhat less than twice the depth of tho trunk at its insertion ; 
anal fin with one or two small anterior spines and from 25 to 30 
articulated rays, its extent slightly more than half that of the 
dorsal. 
Ihe proportions of the dorsal and pelvic fins vary in different 
specimens according to tho state of preservation, though perhaps 
