780 FISHES—ANGUILLIDZ. 
SUB-CLASS TELEOSTEI. THE BONY FISHES. 
Skeleton more or less ossified ; tail homocercal, or at least not evidently heterocercal ; 
optic nerves simply crossing, without chiasma; arterial bulb simple, with two opposite 
valves at its origin; air bladder if present, not cellular. This group comprises the 
great majority of recent fishes (teleos, perfect ; osteon, bone). 
ORDER 6. ENCHELYCEPHALI. THE EELS. 
This order is framed by Professor Cope for the reception of those Eel-like fishes which 
have the following osteological characters. 
Parietals in contact ; lower pair of basihyals wanting; scapular arch suspended to an 
anterior vertebra; no post temporal; no symplectic; maxillary bone absent, or connate 
with the premaxillary, which forms the borderof the mouth. Premaxillaries separated 
on the median line by the ethmoid; superior branchihyals and inferior and superior 
pharyngeals well developed, the latter of four bones. Of these the fourth is largest 
and supports the third which, with the second, is directed forwards. ( Cope.) 
Among the fresh water fishes, the Eels may be known by the serpentiform body, the 
absence of ventral fins and the long and low dorsal and anal which meet around the 
tail; the jaws are well developed and provided with teeth. But one species occurs in 
the waters of Ohio. (Hgchelus, eel; kephale, head.) 
ANALYSIS OF FAMILIES OF ENCHELYCEPHALI. 
*Pectoral fins present; teeth of sides of jaw separated, not forming a continuous 
cutting edge. ; . ‘ . ; : : : : : ANGUILLID&. 6. 
PAMILY VI. ANGUILLIDA. THE EELS. 
Body much elongated, anteriorly cylindrical, compressed behind, covered with mi- 
nute scaies which are imbedded in the skin; mouth rather large, horizontal, the upper 
jaw not projecting; teeth small, in bands, not forming a uniform cutting edge; gill 
openings rather narrow ; dorsal fin beginning at a considerable distance behind the head, 
continuous with the anal around the tail. A single genus, with probably less than ten 
species, although several hundred have been described. The Eels are cosmopolitan, and 
inhabit all sluggish or still waters, whether brackish or fresh, in warm or temperate 
regions. 
Genus 9. ANGUILLA. Thunberg. 
Anguilla, THUNBERG. * * * 
Murena, (LINNZUS) BLEEKER, Atl. Ich. Mur. I. (not of authors generally.) 
Type, Murena anguilla L., equal to Anguilla vulgaris, TURTON. 
Etymology, Latin, anguilla, Greek, egchelus, an eel. 
The characters of this genus are included above. 
