ENCHODONTID.E. 
189 
(Proc. Amer. Phil. Soc. vol. xii. 1872, p. 349) belong to a member 
of the family Dercetidae. The following species are distinguished, 
but are not represented in the Collection :— 
Stratoclus ajpicalis, E. D. Cope, loc. cit. 1872, p. 349, and Vert. 
c> ^aZa<_^Lj 2 rz;i-I/Cret. Form. West (Rep. U.S. Geol. Surv. Territ. vol. ii. 
1875), p. 227, pi. xlix. tigs. 6_8.—Upper Cretaceous 
(Niobrara Group); Smoky Hill River, Kansas. [Jaw 
with teeth ; Cope Collection.] ^ ^^ _j , 
Stratodus oxypogon, E. I). Cope, Proc. Amer. Phil. Soc. vol. xvii. 
(1878), p. 180.—Upper Cretaceous ; Kansas, [Remains 
of jaws ; Cope Collection.] 
p. H 
« 
Family ENCHODONTFDiE. 
Supraoccipital bone not prominent, but extending forwards to 
the frontals and separating the small parietals in the median line ; 
squamosal reduced, only partly covering the otic region, which 
projects laterally ; no basicranial canal; snout not produced ; cheek- 
plates well developed. Mandibular suspensorium vertical or 
inclined backwards, and gape of mouth wide ; premaxilla delicate, 
considerably extended and excluding a great part of the slender 
maxilla from the upper border of the mouth ; teeth fused with the 
supporting bone, not in complete sockets, those on the pterygo¬ 
palatine arcade and dentary the largest. Opercular apparatus 
complete, with few slender branchiostegal rays and no gular plate. 
Vertebral centra well ossified, none with transverse processes; ribs 
not completely encircling the abdominal cavity; a compound 
hypural bone at the base of the tail. Intermuscular bones present. 
Fin-fulcra absent; the rayed dorsal fin never much extended, 
usually near the middle of the back, and sometimes an adipose fin 
behind. Scales delicate or absent; but occasional longitudinal 
series of scutes, the dorsal series, when present, being unpaired. 
The nearest living allies of this extinct family appear to be the 
Odontostomidse and Alepisauridse, in both of which the margin of 
the upper jaw is formed exclusively by the premaxilla, while in the 
first the large teeth are depressible. Only three genera are known, 
Odontostowus^ Omosudis, and Alepisaurus {Flagyodus), all from the 
deep sea. , ^ 
Synopsis of Genera. 
I. One large terminal palatine tooth. 
Dorsal fin in front of anal; no postclavicular 
plate. Enchodus (p. 190). 
