ESPECIALLY MYCTOPHOIDS 71 
Suborder ENCHODONTOIDEI 
Diacnosis. Body relatively shallow and somewhat laterally compressed. 
Parietals separated completely by the supraoccipital ; post-temporal fossa roofed 
or unroofed. Orbitosphenoid and basisphenoid absent. Supraorbital and ant- 
orbital absent. Premaxilla with a fenestrated pedicel ; maxilla untoothed or finely 
toothed ; supramaxillae absent. Palatine bone thick and tumid with a terminal 
palatine tooth ; teeth absent on the vomer. Large number of branchiostegal 
rays. Interoperculum absent. Pectoral fins inserted low down on the flank ; no 
mesocoracoid arch. Pelvic fins abdominal or sub-thoracic. Vertebral elements 
incompletely fused ; epineurals present. Vertebrae variable in number, more than 
half the total being caudal. Fins without spines ; caudal with 19 principal fin-rays, 
17 branched. Caudal skeleton with second ural vertebra present as a half-centrum. 
Scales present only along the lateral line and the mid-dorsal line anterior to the 
dorsal fin. 
Family ENCHODONTIDAE Woodward, Igor 
DiAGNosis (emended). Head deepened, especially posteriorly ; body may be 
deepened in thoracic region. Post-temporal fossa unroofed. Lower jaw long and 
deep behind the constricted symphysis ; articular facet visible from the lateral 
aspect. Operculum convex posteriorly and deeper than it is broad ; preoperculum 
without prominent ventral spine. Pectoral fins larger than pelvic fins and extremely 
low on body. Pelvic fins abdominal. No posterior extension of the cleithrum. 
Lateral line scales do not overlap ; mid-dorsal scutes reduced and not overlapping. 
Genus ENCHODUS Agassiz, 1835 
DiAGNosis (emended). Enchodontidae in which the body tends to become 
shortened and deepened. Vertebral number may be reduced to 37, caudal region 
remaining relatively constant at 25 vertebrae. Pectoral fins only slightly larger 
than pelvic fins. Anal fin short based, arising behind dorsal fin. Dorsal fin short 
based and in the middle of the back. Mid-dorsal scutes reduced and few in 
number. 
TYPE SPECIES. Enchodus lewesiensis (Mantell) 
Remarks. The genus Enchodus, first erected by Agassiz (1835), is known by 
many species. The majority have been erected on fragmentary material consisting 
mainly of isolated teeth or fragments of the jaw bones (see Woodward Igor : Igo- 
205). Only a few species are represented by complete material and two of these 
are described in the following pages. The neurocranium and jaws of Enchodus 
fawjasi Agassiz have been described in detail by Goody (1968). 
