EEL-FISHES. 
1021 
ture of the species may be recognised without difficulty. 
Gunther mentions Leptocephaloids as much as 10 Paris 
inches (270 mm.) long"; and Facciola found larva) of 
the common Conger in the first stage of development 
(Leptocephalus incequalis) that measured 76 — 140 mm., 
while almost typical fry of the same species were only 
75 mm. long. Gunther also considers it probable that 
not all these larvae follow the normal course of deve- 
lopment and become Congers, but that some of them 
— perhaps when they are borne by the current or some 
other agency out into the open sea or too far from the 
coast where the species develops under normal condi- 
tions — may lead a pelagic, but morbid (hydropic) life, 
increasing in size, though never attaining the typical 
structure of their species or propagating themselves. 
Among the Leptocephali of the Royal Museum we find 
a specimen, otherwise uninjured, and taken in the 
middle of the Atlantic, south-west of the Azores (Lat. 
31° 13' N.; Long. 35° 46' W.), that has five vesicular 
dubitable and 63 doubtful species; in 1883 Jordan and 
Gilbert d estimated the number of the species then 
known at about 280. The great variability of form 
indeed deprives any such estimate of conclusive author- 
ity; but the number of species is at all events con- 
siderable enough to necessitate the arrangement of the 
series in several divisions. Bleeker established six 
families within the series. Gunther was of opinion 
that, considering the transition-forms and the varia- 
bility of the Enchelymorphs, the whole series might be 
included within one family {Murcenidm) ; but at the 
same time he established ten subfamilies, the majority 
of which might well lay claim to the rank of distinct 
families. The Scandinavian fauna contains only two 
members of one among these families; but for the 
European fauna several of them possess interest. On 
the English coast there occurs, though seldom, the Me- 
diterranean Mu ram a (Mur am a helena), which we have 
mentioned above, the type of the Gymnothoracida (Blee- 
Fig 274. Leptocephalus Morrisii (?), from the Atlantic; 
tumours — two of large size, occupying the whole 
depth of the body, and three smaller ones, in the dor- 
sal region — full of fluid and with the myomeres more 
or less atrophied. Sickliness and an abnormal manner 
of life might well explain, as Gunther has pointed out, 
the inconstancy both of form and structure that marks 
these larvae. From the Mediterranean 35 species of the 
so-called genus Leptocephalus have been described * 6 , but 
without evidence to show that the specific characters 
are more than individual variations. 
The Enchelymorph series is fairly rich in forms. 
Bleeker c had examined in 1864 more than 250 species. 
In 1870 Gunther adopted in his Catalogue 227 in- 
a Cat. Brit. Mus ., Fish., vol. VIII, p. 143. 
6 Carus, Prodr. Fnce Medit., vol. II, f>. 546. But Carus re 
species distinct* vix describi possint.” 
c Ail. Ichth. Lid. Orient. Ne'erl., tome IV, p. 5. 
d Bull. U. S. Nat. Mus., No. 16, pp. 355, seqq. 
e GOnther ( Deep Sea Fauna , Chall. Exped.) knew 14 such s] 
36, exclusive of the Leptocephaloids. 
taken in Lat. 31° 13' N. ; Long. 35° 46' W. Natural size. 
ker’s Gymnothoracoidei, Gunther’s Murcenidce engy- 
schistce, with narrow slits between the branchial arches), 
a family very rich in forms, especially in India, and with 
naked body, laterally compressed, and no pectoral fins. 
The Enchelymorphs live both in fresh and salt 
water; but most of them are marine fishes. A great 
number are deep-sea forms 6 — some of them taken in 
more than 4,000 fathoms of water ■ — and show reduc- 
tions still more comprehensive than those we have 
described above, the piscine type consequently appear- 
ing in such simplicity that it is sometimes difficult 
to decide in which order the forms have their right- 
place. 
iarks with regard to these species, “Not* specific* tantum variant, ut 
icies, and Vaillant {Exped. Scient. Travailleur, Talisman ; Poissons ) 
