The Apodes, or Eel-like Fishes ' 365 
Hay has recently found, in an example from the Cretaceous 
of Mount Lebanon, remains of distinct ventral fins. These 
traits seem to indicate an almost perfect transition from the 
Isospondylt to the Archenchelt. 
One family may be recognized at present, Urenchelyide. 
The earliest known eel, Urenchelys avus, occurs in the upper 
Cretaceous at Mount Lebanon. It represents the family Uren- 
chelyide, apparently allied to the Anguzllide,, but having a 
separate caudal fin. Its teeth are small, conical, blunt, in 
many series. There are more than 100 vertebre, the last 
expanded in a hypural. Pectorals present. Scales rudiment- 
ary; dorsal arising at the occiput. Branchiostegals slender, 
not curved around the opercle. Uvenchelys anglicus is another 
species, found in the chalk of England. 
Suborder Enchelycephali. — The suborder Enchelycephalt (éy- 
yedus, eel; xkegdadn, head) contains the typical eels, in which 
the shoulder-girdle is free from the skull, the palatopterygoid 
arch relatively complete, the premaxillaries wanting or rudi- 
mentary, the ethmoid and vomer coalesced, forming the front 
of the upper jaw, the maxillaries lateral, and the cranium with 
a single condyle. In most of the species pectoral fins are present, 
and the cranium lacks the combined degradation and speciali- 
zation shown by the morays (Colocephalt). 
Family Anguillide.—The most primitive existing family is that 
of the typical eels, Anguzllide, which have rudimentary scales 
oblong in form, and set separately in groups at right angles with 
one another. These fishes are found in the fresh and brackish 
waters of all parts of the world, excepting the Pacific coast of 
North America and the islands of the Pacific. In the upper Great 
Lakes and the upper Mississippi they are also absent unless intro- 
duced. The species usually spawn in the sea and ascend the 
rivers to feed. But some individuals certainly spawn in fresh 
water, and none go far into the sea, or where the water is entirely 
salt. The young eels sometimes ascend the brooks near the sea 
in incredible numbers, constituting what is known in England 
as “eel-fairs.’’ They will pass through wet grass to surmount 
ordinary obstacles. Niagara Falls they cannot pass, and 
according to Professor Baird “‘in the spring and summer the 
visitor who enters under the sheet of water at the foot of the 
