614 REPORT OP COMMISSIONER OP FISH AND FISHERIES. 
Apterichthys De la Roche, Anu. Mas., xm, 325, 1809 (coccus). 
Ichthyapus Brisout de Barneville, Revue Zoologique, 219, 1847 (acutiroatris). 
Ophisuraphis Kaup, Apodes, 29, 1856 {gracilis). 
Type : Sphagebranchus rostratus Bloch. 
Etymology : 2<pd£, throat ; ppayyia, gills, 
This genus contains several little-known species of small eels remark- 
able for showing no trace of fins in the adult stage. The name Spliage- 
branchus is based on a species which evidently belongs to the genus, 
and has, therefore, clear priority over Ichthyapus and Apterichthys. 
analysis of the species of sphagebranchus. 
a. [Eyes invisible ; tail longer than rest of body; body very slender; mouth small; 
snout pointed, depressed ; uniform brown, speckled with black on the 
head.] (Risso) C^ecus, 42. 
aa. Eyes externally visible. 
b. Tail nearly one-half longer than head and trunk. 
c. [Head 6 in trunk, 17 in total length; flesh-colored with small black spot's.] 
(Peter 8) Anguiformis, 43. 
cc. Head a little more than 4 times in trunk; tail sharp -pointed ; snout sharp; 
cleft of mouth 2^ to 3 in head; gill-slits almost horizontal, converging 
forwards, the isthmus equal to eye, which is 2 in snout. General color 
light brown, slightly dusky on the back and more dusky along the 
lateral line; head mottled with dusky spots Selachops, 44. 
bb. Tail but little longer than head and trunk. 
d. Head more than } length of trunk. 
e. [Head \\ in trunk, 11£ in total length; eye over middle of jaw; body 
slender; tail rounded, a little longer than head and trunk; anterior 
nostril on lower side of snout, its border denticulate.] (Gunther.) 
Acutirostris, 45. 
ee. [Head about 2 in trunk, 5 in total length ; snout very sharp ; eye moder- 
ate, over middle of gape ; tail scarcely as long as rest of body ; color 
plain brown.] (From Bloch’s figure.) Rostratus, 46. 
dd. Headless than £ of trunk, contained 7f in trunk, 9f in tail; snout sharp; 
cleft of mouth 4 in head ; gill-slits small, inferior, directly transverse as 
in Coecula imberbis, the isthmus very narrow, not as wide as eye, which 
is 2 in snout; tail sharp-pointed ; eye before middle of gape; plain- 
brownish, speckled Kendalli, 47. 
42. SPHAGEBRANCHUS CiECUS. 
Murcena cceca Linnaeus, Syst. Nat., x, 245, 1758 (Mediterranean Sea). 
Sphagebranchus coccus Bloch & Schneider, Syst. Ich., 535, 1801 (and of various 
authors). 
Apterichthys coccus De la Roche, Ann. Mus., xm, 325, 1809 (fide Gunther). 
Ophichthys coccus , Gunther, viii, 89, 1870 (copied). 
Coecula apierygia Vahl, Skrivteraf Naturh. Selskabet, 1794, 150 (after Linnaeus), 
Coecilia branderiana Lac^pede, Hist. Nat. Poiss., ii, 135, 1800 (after Linnaeus). 
Sphagebranchus spallanzanii Costa, Fauna Nap., Pesc., tav. 32, f. 1 (fide Gunther). 
Habitat : Mediterranean Sea. 
Etymology : Coccus , blind. 
This species is known to us from descriptions only. 
