596 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxiv. 
to 7; g-ills 3i, the slit behind the last gill very small or obsolete; gill 
rakers rather long and slender; no lal\vrinthiform appendage; air 
bladder and pseudobranchise present, well developed; pyloric cfeca 2 
or 3; gill membranes free from the isthmus. Vertebra 12+14 = 26. 
Fishes of the tropical seas, similar in mode of life to the Chfetodontidte, 
feeding on small marine animals and plants in the coral reefs. Most 
of them are too small to be used as food. They are ver}" active in life 
and the coloration is usually brilliant, sometimes changing much with 
age. The family shows strong affinities with the Labridaj in its gill 
structures and pharyngeals. In other respects it approaches the 
Kyphosida', while the unique character of the simple nostril is shared 
with the Cichlidfe only, from ancestors of which group the Poma- 
centridaB are probably descended. 
I. Scales moderate or large, 25 to 50 in lengthwise series. 
a. Teeth fixed, conical or incisor-like, covering nearly the whole free edge of each 
jaw; carnivorous species. 
h. Teeth conical, not flattened nor incisor-like, 
c. Teeth in one series; preorbital and all the opercular bones serrate, the 
teeth on the opercle and interopercle very strong; dorsal spines 9 to 11; 
scales small (about 50) Amphiprion, 1. 
cc. Teeth in 2 to 4 series, the outer enlarged and bluntish; preopercle entire; 
scales large; body oblong; lateral line wanting on tail; scales large; 
dorsal spines 12 or 13 Chromis, 2. 
bb. Teeth more or less flattened or incisor-like, in 1 or 2 series. 
d. Preopercle and usually preorbital also, sharply serrate. 
e. Teeth entire, mostly uniserial; preorbital not very deep, its edge not 
notched; scales large; dorsal spines 12 or 13 Pomacentrus, 3. 
dd. Preopercle and preorbital strictly entire; snout naked; suborbitals not 
adnate to the cheeks. 
e. Teeth not emarginate, arranged in two series Chrysiptera, 4. 
ee. Teeth emarginate or Y-shaped, in one series; preorbital moderate; 
scales large; dorsal spines 12 or 13 Glyphisodon, 5. 
1. AMPHIPRION Schneider. 
^mp/iipnon Schneider, Syst. Ichth. Bloch, 1801, pp. 47, 200 {ephippium). 
ProchUus (Klein, Pisces Missus, V, p. 60, nonbinomial. ) Bleeker, Maatsch. 
Wet., II, 1877, p. 20 {ephippium). 
Body short and deep, covered with rather small roughish scales, 
about 50 in a longitudinal series; preorbital serrate, without large 
spine; all the opercular bones strongly serrate; teeth in one row, 
small, conical; dorsal spines 9 to 11. Coloration bright, with usually 
one or more sharply defined bluish white cross bands. Tropical seas, 
abounding about coral reefs. 
(fv'yu^i, everywhere; Trpioov, saw.) 
a. Dorsal rays IX, 19; one broad, pearl-colored cross band, on the head and nape. 
frmatus, 1. 
aa. Dorsal rays X, 16; three pearl-colored bands on head and body polymnus, 2. 
