APODAL FISHES OF AMERICA AND EUROPE. 
663 
Genus 43.— LEPTOCEPHALUS. 
(a) Adult Forms. 
Echelus Rafinesque, Caratteri, etc., 63, 1810 (includes species of Conger, Ophisoma, 
and Myrus ; restricted by Bleeker to Myrus). 
Echelus Jordan, Manual Vert., ed. v, 90, 1888 ( conger ) (not Echelus Rafinesque as 
restricted by Bleeker). 
Conger Cuvier, R&gne Animal, ed. n, 1827 (conger). 
Congrus Richardson, Voyage Erebus and Terror, 1844, 107 (conger). 
Conger Bleeker, Gunther, etc. (conger). 
(b) Larval Forms. 
Leptocephalus Gmelin, Syst. Nat., 1150, 1788 (Morrissi: a larval form, probably 
of Conger conger) ; Risso, Europe M^ridionale, 201, 1826. 
Oxyurus Rafinesque, Caratteri, 19, 1810 (vermiformis, a larva). 
Helmictis Rafinesque, Indice d’Ittiologia Sicilians, 62, 1810 (punciatus) a larva. 
Helmichthys Costa, Fauna Napoli, Pesci (diaphanus). 
?? Leptocephalichthys Bleeker, Act. Soc. Sci. Ind. Veerl., 1, Manado., 69 (hypselo- 
soma). 
VI Diaphanichthys Peters, Monatsber. Ak. Wiss. Berl., 399, 1864 (brevicaudus). 
Type: Murcena conger L. 
Etymology : Ae-nzdc;, slender; zetpaAyj, head. 
This genus contains the well known and widely distributed Conger 
eel and three or four closely related species. The earliest generic name 
used for members of the group is that of Leptocephalus , based on a curi- 
ous, elongate, transparent, band-like creature with minute heall and 
very small mouth, found in the waters of Europe, and known as Lep- 
tocephalus morrissi. This has been shown by Gill and Gunther to be 
the young and larval form of Conger conger. A number of genera and 
species of the supposed famity of Leptocephalidce have been described, 
* but there is no doubt that all of them are larvm, some of eels as Conger 
and Nettastoma , others of Isospondylous fishes, as Albula, Elops , Alepo- 
cephalus. Stomias, Fierasfer. Whether these forms are normal young 
or individuals abnormally arrested in development is not certain. Dr. 
Gunther iucliues to the latter opinion, but the observations of Dr. 
Gilbert on the leptocephalous forms of Albula , Elops , and Conger seem 
to point to the former conclusion. For a full discussion of these larval 
forms see Gunther, vm, 136. 
Although as the nam e Leptocephalus has beeu associated for more than 
a century with these larval forms it is a decided inconvenience to ac- 
cord to it precedence as a generic name over Conger. The strict law 
of priority, however, demands its retention, and the tendency among 
systematic zoologists is to recognize as few exceptions as may be to this 
rule. 
The fish described by Jenyns from Tierra. del Fuego under the name of 
Conger punctus (Voyage of the Beagle , Fishes, 143, 1842), and doubtfully 
referred by Gunther to Congromurcena ( Ophisoma) is not an eel at all, but 
belongs to the Lycodidoe and is apparently identical with Maynea pata- 
gonica (Cunningham). It may stand as Maynea puncta. 
