80 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Genus 46. SERRIVOMER Gill & Ryder. 
Nemichthyids with the head behind eyes of an elongated parallelogramic form, with moderately 
attenuated jaws; branchiostegal membranes confluent at posterior margin, but with the branchial 
aperture limited by an isthmus except at the margin, and with lancet-shaped vomerine teeth in a 
crowded (sometimes doubled) row. A single Hawaiian species. (See Section II.) 
Serrivomer Gill & Ryder, Proc. U. S. Nat. Mus. 1883, 260 ( beam ). 
Family XXXI. OPHICHTHYID/E. — The Snake Eels. 
This family includes those scaleless enchelycephalous eels with end of the tail projecting beyond 
dorsal and anal tins; without rudiment of a caudal tin; with anterior nostrils placed in upper lip, 
opening downward; gill-openings not confluent; tongue more or less fully adnate to floor of mouth. 
The species are, for the most part, moderate or small in size, and they are very abundant in the tropical 
seas, especially about coral reefs. The eggs are numerous, of moderate size, similar to those of 
ordinary fishes. Genera about 12; species nearly 100. Many of the species are singularly colored, the 
bands or spots heightening the analogy between them and the serpents. 
Only 8 species of this large family are thus far known from the Hawaiian Islands. 
a. Body without traces of fins anywhere Sphagebranchus , p. 80 
an. Body with distinct dorsal and anal fins. 
h. Vomerine teeth, none ..Leiaranus, p. 81 
66. Vomerine teeth present, 
c. Pectorals present. 
d. Teeth sharp, pointed, some of them often canine or fang-like. 
C. Dorsal inserted over or before gill-opening; canines small Microdonophis, p. 82 
ee. Dorsal behind gill-opening; lips fringed; canines large jSmchysoinophis, p. 83 
dd. Teeth blunt, mostly granular or molar Myrichthys, p. 84 
cc. Pectorals wanting Callechelys , p. 85 
Genus 47. SPHAGEBRANCHUS Bloch. 
This genus contains several little-known species of small eels, remarkable for showing no trace of 
tins in the adult stage. The snout projects beyond the small mouth, giving a shark-like profile, and 
the small teeth are mostly uniserial. The gill-slits are inferior and converging. The name Sphage- 
branchus was based on a species which evidently belongs to the genus. It has therefore clear priority 
over Ichihyapus and Apterichthys. 
This genus is the most simple in structure among the Ophichthyid.se, as Ophichthus is probably the 
most specialized. The loss of fins is doubtless due to degeneration, but Spihagebranchus seems nearer 
the primitive type than Brachysomophis or Ophichthus. 
Sphagebranchus Bloch, Ichthyologia, XII, 79, pi. 419, fig. 2, 1797 (rostralus). 
Cxcilia Lacepede, Hist. Nat. Poiss., II, 135, 1800 (6 r under tana = emeus) \ not Cxcilia L., a genus of Batrachia. 
Apterichthys De la Roche, Ann. Mus. Nat. Hist. Paris, XIII, 325, 1809 (coccus). 
Branderius Rafinesque, Analyse de la Nature, 93, 1815 (coccus). 
Ichihyapus Brisout de Barneville, Revue Zoologique, 219, 1847 (acutirostris) . 
Ophisurapus Kaup, Apodes, 29, 1856 (gracilis). 
34. Sphagebranchus flavicaudus Snyder. Plate 5, fig. 2. 
Head, measured to upper edge of gill-opening, 18 in length, 9.5 in trunk including head, 8.3 in 
tail; depth 3.9 in head; snout 5.5. Snout long, slender, and sharp, projecting beyond upper jaw, tip 
of latter reaching beyond eye a distance equal to diameter of pupil; eye midway between tip of snout 
and angle of mouth, its diameter contained 3 times in length of snout; anterior nostril with a short 
tube on ventral side of snout a little nearer its tip than to border of eye; posterior nostril without 
tube, placed below anterior margin of eye; upper lip with a fold extending from nostril to angle of 
mouth; teeth of jaws in a single series; a group of 4 canines at end of upper jaw, all being beyond 
end of lower jaw when it is closed; a few sharp teeth on anterior part of vomer; gill-openings inferior, 
converging, the distance between them about equal to diameter of eye; width of gill-opening 7.9 in 
head; no fins; tail pointed. 
