70 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
12. Leptocephalus conger (Linnaeus) . Conger Eel; Congrio. 
Dorsal beginning opposite or just behind tip of pectoral; eye 1.5 in snout, 5 to 6 in head; snout 
3.25 to 4.25 in head; gape extending nearly or quite to posterior margin of eye; head 1.8 to 1.86 in 
trunk; tail longer than rest of body; pectoral 3.5 in head; upper lip full, with conspicuous pores. 
Ashy-gray or blackish; vertical fins with black margin; body sometimes (var. niger) entirely black. 
Atlantic Ocean, generally common on both coasts, from Cape Cod to Brazil; also on coasts of Asia 
and Africa; almost cosmopolitan, but not found in the eastern Pacific. It reaches a length of 8 feet, 
and is an important food-fish, especially in Europe. Recorded by Dr. Stahl; not obtained by us in 
Porto Rico. 
(а) Larval Forms. 
Leptocephalus morrissi Gmelin, Syst. Nat., 1150, 1788, Holyhead, England. 
Ophidium pellucidum Couch, Lond. Mag. Nat. Hist., V, 1832, 313, 742, England. 
Leptocephalus gracilis Storer, Mem. Amer. Acad., II, 524, 1839, Massachusetts. 
Leptocephalus spallanzanii, candidissimus, etc., of European writers. 
(б) Adult Forms. 
Mursena supremo margine pinnse dorsalis nigro Artedi, Synon., 40, 2, 1738, Mediterranean. 
Mursena conger Linnaeus, Syst. Nat., X, 245, 1758, Mediterranean Sea; based on Artedi. 
Mursena nigra Risso, Ich. Nice, 93, 1810 (black variety), Nice. 
Anguilla oceanica Mitehill, Jour. Ac. Nat. Sci. Phila. 1818, 407, off New York. 
Conger verus Risso, Eur. M<5r., Ill, 201,1826, Nice. 
Conger vulgaris Cuvier, Regne Animal, ed. II, vol. 2, 350, 1829, France; Gunther, Cat., VIII, 38, 1870. 
Conger rubescens Ranzani, He Novis Spec. Pise. Diss. Prima, 19, pi. V, fig. 5, 1838, Mediterranean. 
Ophisoma obtusa Swainson, Fish., Rep., and Amph., II, 395, 1839, Sicily. 
Conger orbignyanus Valenciennes, D’Orbigny, Voy. Am. M5rid., Poiss., pi. 12, 2, 1839, South America. 
Conger esculentus Poey, Memorias, II, 346, 1860, Cuba; Stahl, l.c., 80, 1883 (misprinted "Conges”). 
Leptocephalus conger, Jordan & Evermann, l.c., 354, 1896. 
Family X. MUR£NESOCID£. 
Scaleless anguilloid eels, with posterior nostril not labial, tongue largely adnate, jaws not excess- 
ively elongate, end of tail surrounded by caudal fin, and pectoral fins well developed. None of these 
characters appears to have in itself great importance, but, according to Dr. Gill, in the genus Murse- 
nesox, the only genus in which the osteology is well known, the characters are such as fully to justify 
family distinction. 
Dr. Gill gives the following diagnosis of the Murxnesocidse : “ Enchelycephalous Apodals with 
the tongue not free, the branchiostegal membrane connecting the opposite sides below, the epipharyn- 
geals reduced to one pair, and the hypopharyngeals linguiform and encroaching on the fourth 
branchial arch.” To this should be added: Gill-openings rather wide; pectoral fins well developed; 
jaws of moderate length; vomer well armed. 
Whether all these characters are found in the other genera commonly associated with the Murse- 
nesox is not yet known. The family, as understood by us, seems divisible into two well-marked 
groups, which are, perhaps, as distinct from each other as from the Echelidse or the Congridte. The 
species of this family are not very numerous, and a large proportion are American. In general 
appearance and habits they approach the congers. All are plainly colored, and some descend to 
rather deep water. One genus represented in Porto Rico. 
MURAiNESOCINAi: 
a. Dorsal and anal fins well developed throughout, the dorsal beginning nearly above gill-opening; snout moderately 
produced; vomerine teeth very strong. 
b. Teeth in jaws in several series; gill-openings wide Mur.enesox, 11 
bb. Teeth in jaws biserial, small; vomer with a series of long, pointed canines; tail about four times as iong as rest of 
body; gill-openings narrow Hoplunnis 
Stilbiscin^;: 
aa. Dorsal and anal fins very low anteriorly, developed chiefly on the tail. 
c. Tail about as long as rest of body; teeth moderate; dorsal beginning before the vent. Body moderately elongate, 
diameter more than one-thirtieth the length; dorsal beginning just before vent Neoconger 
cc. Tail short, little more than half as long as rest of body; teeth all uniserial, unequal, some of them canine-like; 
body very slender, whip-shaped. 
d. Dorsal fin beginning not far behind pectoral Leptoconger 
dd. Dorsal fin beginning behind the vent Stilbiscus 
ddd. Dorsal fin beginning close behind the nape Gordiichthys 
