Maryland Geological Survey 355 



Occurrence. — Matawan Formation. Post 105, Chesapeake and Dela- 

 ware Canal, Delaware ; Magothy Eiver, Anne Arundel County, Maryland. 

 Collection. — Maryland Geological Survey. 



Subclass TELEOSTEI 



Order PHYSOSTOMI 



Family ENCHODONTIDAE Smith Woodward 



( Hoplopleurim: Pictet) 



" 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 pterygopalatine arcade and dentary the largest. Opercular apparatus 

 complete, with few slender branchiostegal rays and no gular plate. 

 Vertebral centra well ossined, none with transverse processes; ribs not 

 completely encircling the abdominal cavity ; a compound hypural bone at 

 the base of the tail. Intermuscular bones present. Pin-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 Odon- 

 tostomidce and Alepisauridce, 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, Odontostomus, 

 Omosudis, and Alepisaurus (Plagyodus) , all from the deep sea." — Smith 

 Woodward, 1901. 



This entirely extinct family comprises large fusiform, laterally com- 

 pressed rapacious fishes, some of which are exceedingly abundant in the 



