THE FISHES OF PORTO RICO. 
333 
Measurements of 15 specimens of Symphurus plagusia, showing variations. 
Locality. 
Total 
length. 
Length to 
base of 
caudal. 
Head. 
Depth. 
D. 
A. 
Scales. 
Color of tail. 
Mayaguez 
146 
137 
5. 25 
3.5 
88 
76 
90 
Black. 
Do . 
92 
85 
5. 33 
3.25 
90 
74 
79 
Pale. 
Palo Seco 
120 
113 
5. 33 
3.05 
88 
t 1 
82 
Verv black. 
Do 
103 
96 
5. 05 
3.43 
95 
80 
86 
Black. 
Do 
94 
87 
5. 12 
3.5 
96 
75 
87 
Do. 
Do 
108 
100 
5.6 
3.6 
96 
83 
88 
Do. 
Do 
109 
103 
6. 44 
3.5 
96 
83 
88 
Do. 
Boqueron 
117 
109 
5.5 
3.5 
96 
79 
83 
Verv dusky. 
109 
103 
5. 15 
3.21 
96 
76 
82 
1 )usky. 
Do 
93. 5 
86 
5.25 
3.5 
93 
82 
Do 
88 
82 
5. 12 
3.25 
91 
75 
78 
Barred. 
Do 
85 
78 
5.2 
3.37 
93 
80 
Do 
68 
64 
5 
3. 66 
93 
78 
78 
Plain pale. 
1 1 ucares 
90 
85 
5.33 
3.5 
92 
75 
87 
Pale. 
Do 
91 
84 
5.25 
3.5 
94 
79 
82 
Do. 
Plagusia, Browne, Jamaica, 445, No. 1, 1756, Jamaica. 
Pleuronectes plagusia Bloch & Schneider, Syst. Ichth., 162, 1801, Jamaica; after Browne. 
Achirus ornatus Lacepede, Hist. Nat. Poiss., IV, 659, 1803, on a specimen “presented by Holland to France." 
Plagusia lessellata Quoy & Gaimard, Voyage Uranie, Zoologie, 240, 1824, Rio Janeiro. 
Plagusia brasiliensis Agassiz, Spix, Pise. Brasil., 89, tab. 50, 1829, Brazil. 
Aphoristia ornata , Poey, Fauna Puerto-Riquena, 341, 1881; Stahl, 1. c., 80 and 166, 1883. 
Symphurus plagusia. Jordan & Evermann, 2709, 1898. 
Family LXXV. ANTENNARIID^. The Frog-fishes. 
Head and body more or less compressed. Mouth vertical or very oblique, opening upward; 
lower jaw projecting; jaws with cardiform teeth; premaxillaries protractile. Gill-openings small, 
pore-like, in or behind lower axils of pectorals. No pseudobranchise. Gills 2.5 or 3; skin naked, 
smooth, or prickly. Pectoral members forming an elbow-like angle. Pseudobrachia long, with 3 
actinosts. Ventral fins present, jugular, near together. Spinous dorsal of 1 to 3 separated, tentacle- 
like spines; soft dorsal long, larger than anal. Pyloric creca none. 
The Antennariiclie comprise about 5 genera and 50 species, inhabitants of tropical seas, “living 
on floating seaweed, and enabled, by filling the capacious stomach with air, to sustain themselves on 
the surface of the water”; therefore widely dispersed by currents in the sea. The different species 
display the most grotesque forms and appearance; and, as Dr. Gunther well says, there is none, 
perhaps, in which the singular organization of the fish is more distinctly seen to be in consonance 
with its habits; and there is none in which mimicry and protective coloration and organization are 
more strongly or more beautifully exemplified. “The habits of all are equally sluggish and inactive. 
They are found in all warm seas and are very bad swimmers. Those found near the coasts lie on the 
bottom of the sea, holding on with their arm-like pectoral fins to seaweeds or stones,” among which 
they conceal themselves. Their colors and dermal filaments resemble the seaweeds very closely and 
render the fish extremely difficult of detection. The species of pelagic habits attach themselves to 
floating Sargassum or other floating seaweed and are carried about by the winds and currents. 
a. Head compressed; a rostral spine or tentacle, followed by 2 larger spines; palatine teeth developed; dorsal spines 
disconnected. 
b. Skin naked and smooth; ventral fins elongate Pterophryne, 161 
bb. Skin covered with prickles; ventral fins short Antennarius, 162 
aa. Head cuboid; a single rostral spine or tentacle, received in a groove; soft dorsal low Chaunax,163 
Genus 161. PTEROPHRYNE Gill. Mouse-fish. 
Body smooth or scarcely granular, short, somewhat compressed, with tumid abdomen; mouth 
small, oblique; palate with teeth; wrist and pectoral fin slender; ventrals elongated; soft dorsal and 
anal vertically expanded. 
Small fishes of fantastic shape in the West Indies and the Gulf Stream. 
a. “Bait” on first dorsal spine bifurcate at tip - histno 
aa. “Bait” on first dorsal spine bulbous, covered with fleshy filaments gibba, 284 
