THE FISHES OF PORTO RICO. 
281 
Family LXI1I. TRIGLID^E. The Gurnards. 
Body elongate, usually more or less fusiform, covered with scales or bony plates. Head externally 
bony, entirely cuirassed with rough, bony plates, some of which are armed with spines; eyes high; 
mouth terminal or subinferior; premaxillaries protractile; maxillary without supplemental bone, 
slipping under preorbital; teeth very small, in bands in jaws, and usually on vomer and palatines; 
gills 4, a large slit behind fourth; pseudobranch ise present; gillrakers various; gill-membranes free 
from isthmus. Ventral tins thoracic, wide apart, separated by a flat area, their rays i, 5. Spinous 
dorsal present, short; soft dorsal similar to anal, which is without spines; caudal narrow, few-rayed; 
pectoral large, with broad base, with 3 lower rays detached, forming feelers. These free rays are used 
chiefly in search for food, turning over stones, exploring shells, etc. Air-bladder present; pyloric 
cseca usually present, few in number. 
Singular-looking fishes, found in all warm seas, comprising 5 genera and about 40 species, some of 
them in rather deep water, these red in color, the others living about rocks. 
a. Palatines, with teeth. 
b. Dorsal spines low, the longest usually much shorter than head; scales moderate, 50 to 80 pores Prionotus, 130 
bb. One or 2 of the dorsal spines greatly elevated, about as long as body; scales large, rough, the pores 10 . . Bellator 
aa. Palatines toothless; scales small. 
c. Lateral line without enlarged bony plates Chelidonichthys 
cc. Lateral line armed with a series of transverse bony plates Tkigla 
Genus 130. PRIONOTUS Lacepede. 
Body subfusiform; profile of head descending to the broad depressed snout, which is much longer 
than the small eye; eyes close together, high up; surface of head entirely bony, bones rough with ridges 
and granulations; scales on head few or none; preopercle with 1 or 2 sharp spines at its angle; opercle 
with a sharp spine; nape with two strong spines; a spine on shoulder-girdle. Mouth rather broad; 
bands of small, almost granular, teeth on jaws, vomer, and palatines; gill-membranes nearly separate, 
free from isthmus; gillrakers rather long. Body covered with small, rough scales, which are not 
keeled; lateral line continuous; scales on breast very small. Dorsal fins distinct, first of 8 to 10 rather 
stout spines, third usually highest, but mostly shorter than head; anal fin similar to soft dorsal; pectoral 
fin with 3 lower anterior rays thickened, entirely free from each other and from fins; ventrals i, 5, 
wide apart, with a flat space between them, inner rays longest. Pyloric caeca in moderate number; 
air-bladder generally with lateral muscles and divided into 2 lateral parts; vertebrae 10 or 11+15. 
Species numerous, all but one being American, representing in America the Old World genus Trigla, 
some in deep water. They are well defined and easily recognized, but vary considerably with age, 
and are not easily thrown into subordinate groups. Most of the characters in the following analysis 
have been taken from adult individuals. Young examples in most cases differ from adults in the 
following respects, in addition to those characters which usually distinguish young fishes: The spines 
on the head are sharper, more conspicuous, and more compressed in the young, and some spines, 
especially those on side of head, disappear entirely with age. The interorbital space is more concave 
in the young. Tire pectoral fins are also much shorter. The gillrakers are longer in the young, and 
proportionately more slender, and some of the color markings — especially the darker cross-shades — are 
more conspicuous, while the spots on body and fins are less so. 
Of the 21 recognized American species of the genus Prionotus 9 are known from the Pacific coast, 
5 from the Atlantic coast of the United States, 5 (one of which is among those occurring on the 
Atlantic coast) from the Gulf of Mexico, while but 3 are known from the West Indies. The majority 
of the species are from rather deep water, and not many are taken in shore collecting. 
a. Mouth comparatively small, maxillary less than a third length of head; mandible usually not extending backward 
as far as vertical from front of eye; generally a more or less distinct cross-groove on top of head behind eye; 
black spot on spinous dorsal usually more or less distinct. 
b. Snout not distinctly birostrate, anterior profile usually not strongly concave. 
c. Pectoral tin long, reaching past front of anal. 
d. Pectoral fin not reaching base of caudal; gillrakers moderate, 8 or 10 developed; snout not strongly emarginate; 
no spine on cheek bone or edge of snout; dorsal spines 10. 
e. Body not very slender, depth 5 in length; head not very small, its length 3 in body; groove across top of head 
behind eye, very conspicuous; interorbital area moderately concave, rather broad, about equal to diameter of 
eye; bones of head comparatively smooth; preocular, postocular, occipital, and nuchal spines low, depressed; 
temporal ridge conspicuous, without spines. Dorsal spines low, second 2.12 in head, first moderately serrate; 
