PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 209 
Vol. VE, No. £4. Washington, D.C. Oct. 5, 1883. 
inner series longer and depressible, longer than teeth of lower jaw. 
Vomer with a long, slender, median canine. 
Anterior nostril in a moderate tube; posterior without tube, above 
front of eye. Mouth capable of being completely closed. Tip of lower 
jaw included. Eye rather large, placed midway between tip of snout 
and angle of mouth, its length about half that of snout; cleft of mouth 
about half length of head. 
Dorsal fin rather high, beginning well in frontof gillopening. Head 
23 in trunk. Head and trunk a little shorter than tail. 
Color rather light yellowish brown, with about 20 blackish rings, 
which are usually about three times the breadth of the interspaces ; 
these rings are somewhat irregular, broadest above, becoming narrow 
below. They extend over the fins, and are very rarely confluent with 
each other. Tip of tail black. Head with 34 rings, which do not meet 
below. Tip of snout in one ring, the top and front of snout on median 
line pale. ‘ 
The typical specimen, 9 inches in length (20385 U. S. Nat. Mus.), was 
obtained at the Galapagos Islands by Captain Herendeen. 
We here use the name Sidera for those species of Murena which have 
the posterior nostrils without tubes and the teeth all sharp. It is, there- 
fore, equivalent to the subgenus Gymnothorax of Giinther, but as the 
proper type of Gymnothorax Bloch is Murena helena L., the name should 
not be used for this division. 
The species of Sidera known from the Pacifie coast of America may 
be thus compared : ; 
a. Dorsal beginning considerably before gill-opening. 
b. Body with many broad, blackish rings; teeth entire, those of upper jaw mostly 
biserial ; of lower, uniserial; body strongly compressed .. CHLEVASTES. 
bb. Body without dark bands or rings; teeth mostly uniserial; body not strongly 
compressed. 
ce. Body and fins closely covered with irregular pale spots, around which the 
dark color forms reticulations; dorsal and anal edged with black ; 
angle of mouth black; larger teeth serrated on posterior margin ; 
Mewdiel etn) GRUM Ke es fasyaiS  c) ja,2 aa mc el on ah oe emene OCELLATA.* 
ce. Body with small yellowish spots; nasal tubes short ; teeth entire.... Dovii.t 
ecc. Body without distinct pale spots or bands. 
* Gymnothorax ocellatus Agassiz, Spix, Pisc. Bras., 1828, 91. West Indies, Gulf of 
Mexico, Brazil, Panama ? (Giinther) (not seen by us on Pacific coast). 
+t? Murena dovii Giinther, Cat. Fish. Brit. Mus., viii, 103, 1870; Murena pintita 
Jordan & Gilbert, Proc. U. S. Nat. Mus., 1881, 346. Mazatlan (Gilbert); Espiritu 
Santo Island (Belding); Panama (Giinther) ; Galapagos Islands (Herendeen). Two 
or three species may perhaps be here confounded, but more probably the markings 
are very variable. 
Proc. Nat. Mus. 88——14 
