Dr. A. Giinther on new American Fishes. 201 
25. MicropEsMus piPpus, n. g. et sp. Of this we have re- 
ceived only a single small example ; and as it is not in a perfect state 
of preservation, we cannot decide whether it should be referred to 
the Blennoids or Gadoids, or whether it is the type of a distinct 
family. However, we may hope that Capt. Dow will succeed in ob- 
taining more specimens. 
MicrRoODESMUS. 
Body much elongate, eel-like, covered with rudimentary scales ; 
head rather short, with obtuse snout, narrow cleft of the mouth, 
and prominent lower jaw. Eyes minute. Teeth in both jaws mi- 
nute ; palate toothless. The gill-opening is reduced to a small slit 
in front of the pectoral fin. Vertical fins united by a membrane, 
but the caudal can be easily distinguished from the two other fins. 
Dorsal fin very long, composed of flexible, undivided rays, like the 
anal. Pectorals short; ventrals thoracic, each reduced to a single 
ray. Vent in the middle of the total length. 
MICRODESMUS DIPUS. 
Droo. A. 34. C.16. P.12. Y.J. The depth of the body 
is about one-eighteenth of the total length; the length of the head 
one-eleventh. The head is rather compressed, the snout short, the 
mouth very narrow, and the lower jaw very prominent. The mi- 
nute eye is lateral and in the anterior third of the length of the head. 
The dorsal fin commences at a distance from the occiput which is 
somewhat less than the length of the head; it is nearly even, and 
the rays are very distinct, the interradial membrane being thin and 
transparent. The anal fin commences immediately behind the vent. 
The caudal rays are much more slender and more closely set than 
those of the dorsal and anal; the caudal fin is rounded, two-thirds 
of the length of the head. Pectorals as long as the ventrals, and 
half as long as the head; the latter fins are close together, and in- 
serted a little behind the root of the pectoral. Upper parts uniform 
brownish olive. 
The single specimen is 43 inches long. 
26. ANABLEPS Dovi, Gill. 
II. Species collected at Colon. 
1. Prist1POMA MELANOPTERUM, Cuv. & Val. 
2. PomacanTuus Paru, Gthr. 
3. SpHyr2@NA Picupa, Bl. Schn. 
III. Species from the Lake of Managua, Nicaragua. 
1. HeROs LABIATUS, 0. sp. 
D.~. A: =. L. lat. 32. L. transv. 6/13. .The anterior por- 
pails ane 
tions of the upper and lower lips are much enlarged, each forming a 
