336 
ACTINOPTURYGIl. 
Suborder VI. APODES. 
Notochord more or less persistent, but the vertebral centra 
always complete constricted cylinders, none coalesced ; tail tapering, 
usually without expanded or fused neural or hicmal supports at the 
extremity. Symplectic bone absent ; mandible simple, each ramus 
consisting only of two elements (dentary and articulo-angular). 
Pectoral arch not suspended from cranium ; precoracoid arc 
absent ; iufraclavicular plates absent ; pectoral fin with more than 
five basals. Pelvic fins absent. Scales rudimentary or absent. 
In the living forms — air-bladder, when present, connected with e 
oesophagus by a duet in the adult (physostomous), optic nerve, 
decussating, intestine without spiral valve, and reproductive organs 
without efferent ducts. 
Family MUR/KNID2E. 
Irunk much elongated, the caudal region being relatively vcr « 
long. Parietal bones large and meeting in a median suture , 
squamosal suturally united with parietals and covering the greater 
part of the otic region. Premaxilhe small and fused with t 
ethmoidal rostrum ; maxilla well-developed, forming most of t ® 
upper border of the mouth : ptery go-palatine arcade much induce ^ 
or rudimentary. Branchial and opercular apparatus usually mor 
°r less reduced ; generally a few delicate hranchiostegal r _^‘ 
Vertebrae very numerous, those of the abdominal region with s or 
and broad transverse processes, small and delicate ribs, and very 
short neural spines. Intermuscular bones present. Fin-iu c < 
absent; fin-rays articulated and divided distally ; dorsal and ana^ 
fins excessively extended, and a separate caudal fin almost alway- 
absent. 
The oxtinct species of this family arc too imperfectly known to 
be generically determined with certainty. It is evident, however, 
that they represent some of the more generalised types ; and t 
Cretaceous genus mentioned below is unique in retaining a noim 
caudal fin. 
A figure of the skeleton of Anguilla is published by A gass > 
Poiss. Foss. vol. v. pi. D. Some illustrations of cranial osteology 
are given by Storms, Bull. Soc. Beige Geol. vol. x. (1898), ph vl - 
