168 
ACTIXOPTEKYGII. 
are deeper than long, but those more posteriorly are about 
as eep as long; all are marked by very delicate hm^ 1 
tur inal ridges. Traces of slender ribs occur, and all t 
neural arches bear curious laminar expansions. Porti° D ® 
o the pelvic fin-supports ( plv .) are distinguishable, an 
there are a few indications of very thin scales. 
EnnisMll en CoU- 
The following specimen seems to belong to a species of Enchelur**, 
but is not satisfactorily determinable:— 
P, 9248. Imperfect distorted fish, nearly as large as the type s P e ' 
cimen of E. anglicus, wanting caudal extremity ; 
Cretaceous, Hakel, Mt. Lebanon. The characteristic 
cranium is exposed from above, and the left maxilla a' 1 
mandibular ramus are well shown. There are also rcm a,IlS 
of a tubercular tritoral dentition on some of the inu cr 
bones of the month. The expansions of the neural arc 
cannot be seen. Remains of the pelvic, dorsal, and am 
fins occur. The scales are marked by radiating groove 
in their covered portion. Lewis Co 
Family NOTACANTHIDiE. 
Trunk much elongated, the caudal region slender and taperwfb 
with or without a diminutive caudal fin. Parietal bones partly in 
contact, hut not completely excluding the supraoecipital from 1 1 
cranial roof ; squamosals suturally united with parietals and com 
pletoly covering the otic region ; snout a little produced ; c ^ e ® 
plates very delicate. Mandibular suspensorium inclined forwar 
and gape of mouth small ; premaxilla extended and excluding t 
maxilla from the upper border of the mouth ; teeth slender, never 
much enlarged. Opercular apparatus complete, with a few branchi 
ostegal rays, but no gnlar plate. Vertebral centra much constricte , 
those of the abdominal region with very short and broad transverse 
processes ; ribs long and slender, inserted just below the neura 
arches. Intermuscular bones present, sometimes fused with t 
ribs. Pectoral arch connected with the skull by ligament. F ]n 
fulcra absent ; paired fins well-developed, the pelvic pair beii'.- 
remote; dorsal fin rudimentary, its supports beiDg widely space > 
and the rays, when present, being represented chiefly by 8® 
spines ; anal fin low and much extended, its anterior portion f*t 
least spinous. Scales thin and cycloid ; lateral line distinct alon„ 
the upper part of the flank. 
