1022 
SCANDINAVIAN FISHES. 
Fam. ajvguillidje. 
Gill-slits ( between the branchial arches) wide; gill- openings (■ in the skin ) widely separated. Heart situated just 
behind the branchial cavities. Vertical fins well-developed and confluent round the tail. Pectoral fins present. 
Anal fin separated from the tip of the snout by a distance of more than twice the length of the head. Posterior 
nostrils distant from the margin of 
Among Gunther’s Platyschistce some (the Synaplio- 
branchidce ) are characterized by the downward removal 
of the gill-openings towards the ventral side and their 
union. Others (the Ptyobranchidce ) are marked by so 
great a prolongation of the forepart of the body that 
the heart is situated far behind the branchial cavity. 
Others again (the Nemich thy idee) have the vent far ad- 
vanced, close to the gill-openings or separated from 
them by a distance less than the length of the head, 
and the beginning of the anal tin just behind this 
point. In others (the Saccopharyngidce “) the mouth 
the upper lip. Tongue with free tip. 
and pharynx are developed into a monstrous, funnel- 
shaped gorge, so large that it exceeds the abdominal 
cavity in length. Another division (the Ophichthyidce 
and Myridce, the former with Unless tip of the tail) 
are distinguished by a singular downward removal of 
the nostrils, sometimes quite to the margins of the 
upper lip. Some (the Murcenesocidce) are without free 
tongue; others (the Heterocong rides ) are similar in all 
these respects to our common Eel, but destitute ot 
pectoral fins. The rest compose the family that has 
its most marked type in the 
Genus ANGUILLA. 
The slimy body furnished with scales immersed in the skin. 
By this solitary character it is always possible to 
recognise one of the so-called Fresh-water Eels b , all 
other distinctions being far too inconstant to be im- 
plicitly relied on. Another character, which is not 
peculiar, however, to Anguilla , though within the Scan- 
dinavian fauna it is sufficient to denote the genus, and 
besides has the advantage of being more conspicuous, 
consists in the fact that the tip of the snout falls short 
of the point of the lower jaw, or at least does not 
project beyond it. 
“An infinite number of species,” says Gunther, 
“have been described; but most are so badly charac- 
terized, or founded on individual or so trivial cha- 
racters, that the majority of ichthyologists will reject 
them.” Kauf c , who was the greatest authority on 
this head until Gunther’s time, adopted no less than 
49 species; Guntiikr' z reduced the number to 23. Da- 
reste* acknowledged only 4 or possibly 5. As Gun- 
ther has remarked-'’, the genus is known throughout 
the Tropical and Temperate Zones, with the excep- 
tions of South America, the west of North America, 
and Western Africa. In Scandinavia and the rest 
of Europe only one species is recognised at the pre- 
sent day. 
° For the Saccopharyngidce see G-ill and Rydeb (Proc. U. S. Nat. Mus., vol. VI, p. 262; vol. VII, p. 48), who founded a separate 
order ( Lyomeri ) to receive this family, and Vaillant ( Exped . Scient. Travailleur, Talisman , Poissons, p. 193), who considered them to be as 
nearly allied to the Anacanthines as to the Enchelymorphs. Among their peculiarities it should first be remarked that the number of the 
branchial arches is 5 instead of 4, the usual number in the Teleosts. 
6 Fresh-water or at least brackish-water fishes indeed occur within other Enchelymorph genera, as in Gymnothorax , Pisoodonophis, 
Sphagebranchns , Moringua, and Murcenesox ; but in these genera salt-water Eels predominate, and they are besides entirely foreign to the 
Scandinavian fauna. 
c (Jatal. Apodal Fish., Brit. Mus. (1856), p. 32. 
d Cat. Brit. Mus., Fish., vol. VIII, p. 23. 
e Arch. Zool. Experim., tome IV, p. 224. 
f Introd. Study of Fishes, p. 671. 
