74 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
FAMILIES OF HAWAIIAN APODES. 
a. Enchelycephali: Gill-openings well developed, leading to large interbrancliial slits; tongue present; opercle and 
branchial bones well developed; scapular arch present. 
b. Body covered with linear, imbedded scales Synapliobranehidce, p. 74 
bb. Scales wholly wanting; eggs, so far as known, of moderate size, much as in ordinary fishes, 
c. Tip of tail with a more or less distinct fin, the dorsal and anal fins confluent around it; coloration always plain, 
brownish, blackish, or silvery, the fins often black-margined; posterior nostril without tube, situated 
entirely above the upper lip; tongue broad, largely free anteriorly and on sides; pectorals well developed. 
Leptncephalidx, p. 74 
cc. Tip of tail without rays, projecting beyond the dorsal and anal fins (not filiform); posterior nostril on the edge of 
upper lip; anterior nostril near tip of snout, usually in a small tube; tongue usually adnate to the floor of 
mouth; coloration frequently variegated Ophichthyidx, p. 80 
aa. Colocephali: Gill-openings small, roundish, leading to restricted interbranchial slits; tongue wanting; pectoral fin 
(typically) wanting; opercle feebly developed; fourth gill-arch modified, strengthened, and supporting 
pharyngeal jaws. 
d. Scapular arch obsolete or represented by cartilage; heart not far back; pectorals wanting; skin thick; coloration 
often variegated... Murxnidse, p. 87 
Family XXVII. SYNAPH0BRANCHID4:. 
This group consists of deep-sea eels, differing from the Anguillidx in having the gill-opening 
externally confluent into a single slit. The following diagnosis is given by Dr. Gill: 
“Enchelycephalous Apodals with conic, pointed head, moderate opercular apparatus, lateral 
maxillines, cardiform teeth, distinct tongue, inferior branchial apertures discharging by a common 
aperture, continuous vertical tins, pectorals well developed, scaly skin, and nearly perfect branchial 
skeleton.” 
Body eel-shaped, covered with linear, imbedded scales placed at right angles, as in Anguilla. 
Lateral line present; head long and pointed, the snout produced; mouth very long, the eye being 
over the middle of its cleft; jaws about equal; teeth small, sharp, in a broad band in each jaw, 
becoming a single series anteriorly; those of inner series in upper jaw and of outer series in mandible 
somewhat enlarged; vomerine teeth in a narrow band anteriorly; gill-openings inferior, horizontal, 
close together, convergent forward, somewhat confluent at the surface, but separated by a considerable 
isthmus within; branchiostegals peculiarly formed, in moderate number (about 15), attached to the 
sides of the compressed ceratohyal and epihyal, slender, abbreviated, and moderately bowed, not 
being curved up above the opercle; tongue long, free only at the sides; nostrils large, the anterior 
with a short tube, the posterior before the lower part of the eye; pectoral well developed; dorsal low, 
beginning behind vent; anal longer than dorsal, rather high, its rays slender, branched, not embedded 
in the skin; vertical fins confluent around the tail; vent near the anterior fourth of body; muscular 
and osseous systems well developed; stomach very distensible. Deep-sea fishes. 
Genus 41. SYNAPHOBRANCHUS Johnson. 
Dorsal beginning behind vent. This genus contains 2 or 3 species, deep-sea fishes from the 
Atlantic and Pacific. 
The single Hawaiian species of this genus is fully described in Section II. 
Synaphobranclius Johnson, Proc. Zool. Soc. Lond. 1862, 169 ( kaupii ). 
Family XXVIII. LEPTOCEPHALIDtE. — T he Conger Eels. 
This family includes those eels which are scaleless and have the tongue largely free in front; the 
body moderately elongate; the end of the tail surrounded by a fin; the posterior nostril remote from 
the upper lip and near front of eye; and the pectoral fins well developed; lower jaw more or less 
included; teeth on sides forming a cutting edge; lateral line well developed. All the species are 
plainly colored, grayish or dusky above, silvery below. Species found in most warm seas, usually at 
moderate depth. Most of them undergo a metamorphosis, the young being loosely organized and 
transparent, band-shaped, and with very small head. The body grows smaller with age owing to the 
compacting of the tissues. The two genera found in the Hawaiian Islands are not well separated and 
should perhaps be considered as one. 
