SCOPELIDJS. 
253- 
portions. Paired fins nearly equal in size, the pelvic pair inserted 
midway between the pectorals and the anal; dorsal fin occupying 
about one third of the back, arising opposite the pelvic pair, and 
comprising 17 or 18 divided rays in addition to the anterior 
undivided rays; anal fin less extended than the dorsal, but with 
17 divided rays, and arising opposite the hinder half of the 
dorsal; caudal fin apparently more deeply forked than in the type 
species. 
Form. Loc. Upper Cretaceous : Hakel, Mt. Lebanon. 
P. 4865. The t 3 *pe specimen, wanting the anterior half of the head,. 
and measuring about 0T05 in length from the pectoral 
arch to the extremity of the caudal fin. The opercular 
apparatus is short and deep, and there are 7 or 8 
branchiostegal rays in advance of the few stout rays 
noted by W. vonderMarck in the Westphalian specimens.- 
The axial skeleton and fins are well preserved, except 
the anterior rays of the dorsal and anal. The trunk is 
slightly deepened by crushing, and the dorsal margin in 
front of the fin is marked by curious crimpings, which 
are suggestive of hard, possibly serrated ridge-scales. 
The large smooth scales of the flank displa.y a few 
radiating grooves on their covered portion. Lewis Coll. 
Genus OPISTHOPTERYX, Pictet & Humbert. 
[Houv. Eech. Poiss. Loss. Mt. Liban, 1866, p. 78 (O 2 nsto 2 otery.v).^ 
Head relatively large and trunk elongated, its maximum depth 
at the opercular apparatus. Mandibular suspensorium much 
inclined backwards, and cleft of mouth wide, extending below the 
orbit, which is very large and forwardly placed; teeth minute ; 
gill-rakers large and robust. Vertebral centra not longer than 
deep, longitudinally striated, between 50 and 60 in total number, 
about half caudal and half abdominal; ribs very slender ; separate 
and relatively stout sigmoidally bent neural spines in the abdominal 
region. Pectoral fins elongated, but not extending beyond the 
pelvic pair, inserted close to the ventral border; pelvic fins some¬ 
what smaller; dorsal and anal fins short-based, very deep and 
acuminate, the former placed in the middle of the back, the latter 
arising opposite its hindermost rays; caudal fin large, deeply 
forked, with slender acuminate lobes. Scales thin, but apparently 
uniform and covering the whole trunk. 
