THE FISHES OF PORTO RICO. 
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Family L. POMACENTRID^. The Demoiselles. 
Body short, deep, compressed, covered with ctenoid scales of varying size; lateral line wanting 
posteriorly; mouth small, usually with rather strong teeth, either conic or incisor-like; vomer and 
palatines toothless; nostril single on each side, nearly round; preopercle with its posterior edge largely 
free, serrate or entire; preorbital sheathing the small maxillary; dorsal fin single, with numerous 
strong spines, spinous portion longer than soft, which is similar to soft anal, both fins scaly at base; anal 
spines 2; ventral fins thoracic, i, 5, anterior rays longest, usually filamentous; a scaly appendage at base 
of ventral. Lower pharyngeals fully united; branchiostegals 5 to 7; gills 3.5, slit behind last gill very 
small or obsolete; gillrakers rather long and slender; no labyrinthiform appendage; air-bladder and 
pseudobranchise present; pyloric caeca 2 or 3; gill-membranes free from isthmus. Vertebra* 12-|- 14=26. 
Fishes of tropical seas, similar in mode of life to the Chxtodonlidx, feeding on small marine 
animals and plants in the coral reefs. Genera 15; species about 180, most of them too small to be used 
as food. They are very active in life and the coloration is usually brilliant, sometimes changing much 
with age. The family shows strong affinities with the Labridx in its gill-structures and pharyngeals. 
In other respects it approaches the Kyphosidx, while the unique character of the simple nostril is 
shared with the Gichlidx only, from ancestors of which group the Pomacentridx are probably descended. 
I. Scales large, 25 to 40 in lengthwise series. 
Pomacentrinas: 
a. Teeth fixed, conical or incisor-like, covering nearly whole free edge of each jaw; carnivorous species. 
b. Teeth conical, in two to four series, outer enlarged and bluntish; preopercle entire; scaleslarge; body oblong, depth 
2.5 to 1.33 in length; lateral line wanting on tail Chromis 
bb. Teeth more or less flattened or incisor-like, in one or two series. 
c. Preopercle, and usually preorbital also, sharply serrate. 
d. Teeth entire, strictly uniserial in each jaw; preorbital not very deep, its edge not notched; snout scaly; lower jaw 
naked Eupomacentrus, 104 
cc. Preopercle and preorbital strictly entire; snout naked. 
e. Teeth emarginate or Y-shaped Abudepduf, 105 
Microspathodontinse: 
aa. Teeth movable, incisor-like, in one row on front of each jaw; lower jaw weak, with teeth along its front only; 
preopercle and preorbital entire; snout scaled almost to lips; preorbital notched behind nostril; lower limb of 
preopercle scaled; soft dorsal and anal elevated; caudal deeply forked; soft anal rather long, of 14 or 15 rays; 
herbivorous species Microspathodon 
Genus 104. EUPOMACENTRUS Bleeker. Pescados Azules. 
Body ovate, deep, and compressed, profile steep, usually rounded. Head moderate, nearly as 
deep as long, snout scaly, lower jaw naked. Mouth quite small, terminal, jaws equal; each jaw armed 
with a single close-set series of compressed, immovable teeth, which are truncate at tip. Gillrakers 
long; preopercle more or less serrate; preorbital serrate. Scales large, strongly ctenoid, lateral line 
running parallel with back to near end of dorsal fin, at which point it ceases. Dorsal fin continuous, 
with 12 or 13 low stout spines; membrane of spinous dorsal usually not deeply incised nor lobed; 
soft part- more or less elevated, its last rays gradually shortened; lower limb of preopercle usually more 
or less scaly; preorbital narrow, without deep notch; anal fin similar to soft dorsal, with 2 spines, of 
which the second is much the larger; soft rays 12 to 16; dorsal spines with a sheath of large scales, 
membranes of both dorsal and anal covered high up with small scales; caudal fin more or less forked, 
lobes rounded; lower pharyngeals triangular; branchiostegals 5 or 6. 
Species numerous in the tropical seas, chiefly American, and extremely variable in form and 
color, the brilliant coloration apparently dependent on surroundings. The species are little known 
and the classification of those found in the West Indies is not wholly satisfactory. 
a. Upper anterior profile of head arched. 
b. Depth of body moderate, 1.75 to 2.25 in length, without caudal. 
c. Lower posterior half of body dark, like anterior half; caudal fin mostly dusky. 
d. Pectoral fin not edged with white. 
e. Depth of body 1.75 in length of body (without caudal); side with faint cross-streaks. - adustus 
ee. Depth of body 2 to 2.25 in length. 
/. Opercle without distinct dark spot; caudal not tipped with orange. 
g. Anal without distinct blue spot in its posterior axil, except in young. 
h. Head with few if any small accessory scales. 
i. Base of pectoral without black spot or with but one fuscus, 180 
Base of pectoral with two black spots diencseus 
