Dec. 28, 1916. FisHEs oF PANAMA— MEEK AND HILDEBRAND. 349 
Family XI. Gobiidz. 
Body oblong or elongate; teeth various, usually small; premaxillaries 
protractile; gill-openings usually rather small, the membranes attached 
to the isthmus; opercle unarmed; preopercle unarmed or with a short 
spine; orbital margin not free, continuous with skin of head; lateral line 
wanting; scales present or wanting; dorsal fins 2, separate or connected, 
the first composed of 2 to 8 slender spines; the second dorsal preceded 
by a single weak spine; margin of caudal fin convex; anal usually similar 
to second dorsal; ventral fins close together, separate or united, when 
united forming a sucking disc, consisting of I, 5 or rarely of I, 4 rays, in- 
serted under base of pectorals; pectoral fins with a broad subvertical base. 
Most of the representatives of this family are marine, but some of 
them enter fresh water and rivers. Only the latter of the Panama 
species are discussed in the present paper. 
KEY TO THE GENERA. 
a. Ventral fins separate. 
b. Vomer with villiform teeth; gill-openings extending forward to 
below eyes. Philypnus, p. 350. 
bb. Vomerine teeth wanting; gill-openings not extending forward to 
below eyes. 
c. Head very broad; eyes lateral; jaws anteriorly of equal length; 
teeth compressed at apices; gill-rakers numerous, well developed, 
in 2 series on each arch. Intestinal canal long; species herbi- 
verous. Dormitator, p. 353. 
cc. Head narrower; eyes lateral or not; lower jaw more or less pro- 
jecting; teeth all pointed; gill-rakers few, poorly developed. 
Intestinal canal short; species carniverous. 
d. Preopercle with a small, sharp, concealed spine at its lower poste- 
rior angle. Eleotris, p. 356. 
dd. Preopercle unarmed. 
e. Scales very small, 100 or more in a lateral séries. 
Guavina, p. 360. 
ee. Scales larger, usually fewer than 40 in a lateral series. 
f. Dentary bones broad, expanded, meeting under posterior angle 
of mouth, leaving an oval-shaped, naked patch at chin. 
Leptophilypnus gen. nov., p. 361. 
ff. Dentary bones narrow, not nearly meeting under posterior angle 
of mouth. 
g. Head broad depressed; eyes superior; head and chest naked. 
Microeleotris gen. nov., p. 362. 
